[Pw_forum] possible bug in scatter_forw.f90
Dear Manoj On Tuesday 21 October 2008 00:01, Manoj Srivastava wrote: > Dear Alexander, > Thank you very much for your answer. I have one more question, it seems > my list of questions is never gonna end :( It is always a pleasure when there is someone going through the code written by you and trying to understand what is there after all :-). > this is about init_gper.f90 subroutine. where you calculate > > |G+k|^2 > the expression - > norm2=(((il+xyk(1,ik))*bg(1,1)+(jl+xyk(2,ik))*bg(1,2))**2+ & > ((il+xyk(1,ik))*bg(2,1)+(jl+xyk(2,ik))*bg(2,2))**2)* & > > i believe is |G+k|^2. How do you get above expression in the code for > this? norm2 is indeed |G_perp+k_perp|^2, where G_perp=il*b_1+jl*b_2 and 2d vector k_perp=xyk(1,ik)*b_1+xyk(2,ik)*b_2 and you indeed select out those G_perp+k_perp which satisfy (G_perp+k_perp)^2 I tried to work it out but could not get this. You even have g.k > term! > I guess i would have more understanding once i understand how did > you define Gper in the fourier transform, > V(rper,z)=sum(gper)[exp(i*gper*rper) V(gper,z) > Is gper just gx and gy, and then you rotate your axis to get > bg(1,1),bg(1,2), bg(2,1) and bg(2,2)? Would you mind explaining? The potential V(z,G_perp) is calculated for the full set of 2d G_perp related to the real space discretization of r_perp=(x,y). V(z,G_perp) <--FFT--> V(z,r_perp). G_perp=il*b_1+jl*b_2, il=1..nrx, jl=1..nry, where nrx and nry are in fact nr1s and nr2s of pw.x and are defined by the cut-off ecutwfc. This potential is then used in the subroutine local.f90. Hope this helps, Alexander > > Regards, > Manoj > > On Mon, 20 Oct 2008, Alexander wrote: > > Dear Manoj > > > > On Thursday 16 October 2008 23:15, Manoj Srivastava wrote: > > > Dear Alexandar, > > > Thank you very much. Your answers make sense and now i have better > > > understanding of the subroutine scatter_forw.f90. I have one question > > > about poten.f90 subroutine, where you calculate the V(p,gper) in each > > > slices of the slab(equation 15). I have a question about Gz, which is > > > 2*pi*q/L, with [-N/2]+1<=q>=[N/2]. Now in the code at the line at the > > > line 60, you have Gz multiplied with bg(3,3). I kind of understand this > > > is because 3rd direction is perpendicular to xy plane, > > > > Exactly. As it is implemented now pwcond deals with systems > > having monoclinic unit cell, i.e. such that a3 is perpendicular to both > > a1 and a2 (a1 and a2 are not necessary orthogonal one to another) and the > > direction of transport is a3. This seems to us the most general setup for > > transport and I do not think we should consider at the moment the > > situation where the a3 is not perpendicular to the xy plane. > > > > Best regards, > > Alexander > > > > > but not totally clear > > > about it. Would you mind explaining? my other question is when > > > reciprocal space vectors b1, b2 and b3 are not orhogonal to each other, > > > which is more general case, then should not we take bg(1,3) and bg(2,3) > > > in there too? > > > Thank you once again for listening to my questions and i hope i am > > > not bothering you too much. > > > > > > Regards, > > > Manoj Srivastava > > > Physics Graduate Student > > > Department of Physics > > > Gainesville, FL, USA. > > > > > > have On Wed, 15 Oct 2008, Alexander wrote: > > > > Dear Manoj > > > > > > > > On Tuesday 14 October 2008 17:49, Manoj Srivastava wrote: > > > > > Dear Alexader, > > > > > > > > > > Thank you very much for your reply. I was out of town and could > > > > > not see the message till yesterday. I have some questions on it, it > > > > > would be great if you could answer them. > > > > > > > > > > On Fri, 10 Oct 2008, Alexander wrote: > > > > > > Dear Manoj > > > > > > > > > > > > On Friday 10 October 2008 05:20, Manoj Srivastava wrote: > > > > > > > Any follow ups on the message below? Alexander? > > > > > > > > > > > > > > Regards, > > > > > > > Manoj > > > > > > > > > > > > > > On Wed, 8 Oct 2008, Manoj Srivastava wrote: > > > > > > > > Dear All, > > > > > > > > Is any body familiar with the scatter_forw.f90 subroutine of > > > > > > > > PWCOND? I think there is a bug in this subroutine at the > > > > > > > > place where you calculate intw2, which is z integration of > > > > > > > > nonlocal wavefunction with beta function. I have looked up > > > > > > > > the necessary formulae in the Choi & Ihm's paper (PRB 59, > > > > > > > > 2267, Jan 1999). In the paper, nonlocal wavefunction has 3 > > > > > > > > terms, one of which contains beta function, say W. The other > > > > > > > > two parts dont have any W in them, rather they are just plane > > > > > > > > wave solution. (Please have a look at equation 24 and 26 of > > > > > > > > the paper ). So, when we are doing z integration of nonlocal > > > > > > > > wavefunction with beta function W, we should have three > > > > > > > > terms, one of which should contain two W, but rest should > > > > > > > > just have one W. On the other
[Pw_forum] possible bug in scatter_forw.f90
Dear Alexander,
Thank you very much for your answer. I have one more question, it seems
my list of questions is never gonna end :(
this is about init_gper.f90 subroutine. where you calculate
|G+k|^2 Dear Manoj
>
> On Thursday 16 October 2008 23:15, Manoj Srivastava wrote:
> > Dear Alexandar,
> > Thank you very much. Your answers make sense and now i have better
> > understanding of the subroutine scatter_forw.f90. I have one question
> > about poten.f90 subroutine, where you calculate the V(p,gper) in each
> > slices of the slab(equation 15). I have a question about Gz, which is
> > 2*pi*q/L, with [-N/2]+1<=q>=[N/2]. Now in the code at the line at the line
> > 60, you have Gz multiplied with bg(3,3). I kind of understand this is
> > because 3rd direction is perpendicular to xy plane,
> Exactly. As it is implemented now pwcond deals with systems
> having monoclinic unit cell, i.e. such that a3 is perpendicular to both a1
> and
> a2 (a1 and a2 are not necessary orthogonal one to another) and the direction
> of transport is a3. This seems to us the most general setup for transport and
> I do not think we should consider at the moment the situation where the a3 is
> not perpendicular to the xy plane.
>
> Best regards,
> Alexander
>
> > but not totally clear
> > about it. Would you mind explaining? my other question is when reciprocal
> > space vectors b1, b2 and b3 are not orhogonal to each other, which is
> > more general case, then should not we take bg(1,3) and bg(2,3) in there
> > too?
> > Thank you once again for listening to my questions and i hope i am
> > not bothering you too much.
> >
> > Regards,
> > Manoj Srivastava
> > Physics Graduate Student
> > Department of Physics
> > Gainesville, FL, USA.
> >
> > have On Wed, 15 Oct 2008, Alexander wrote:
> > > Dear Manoj
> > >
> > > On Tuesday 14 October 2008 17:49, Manoj Srivastava wrote:
> > > > Dear Alexader,
> > > >
> > > > Thank you very much for your reply. I was out of town and could not
> > > > see the message till yesterday. I have some questions on it, it would
> > > > be great if you could answer them.
> > > >
> > > > On Fri, 10 Oct 2008, Alexander wrote:
> > > > > Dear Manoj
> > > > >
> > > > > On Friday 10 October 2008 05:20, Manoj Srivastava wrote:
> > > > > > Any follow ups on the message below? Alexander?
> > > > > >
> > > > > > Regards,
> > > > > > Manoj
> > > > > >
> > > > > > On Wed, 8 Oct 2008, Manoj Srivastava wrote:
> > > > > > > Dear All,
> > > > > > > Is any body familiar with the scatter_forw.f90 subroutine of
> > > > > > > PWCOND? I think there is a bug in this subroutine at the place
> > > > > > > where you calculate intw2, which is z integration of nonlocal
> > > > > > > wavefunction with beta function. I have looked up the necessary
> > > > > > > formulae in the Choi & Ihm's paper (PRB 59, 2267, Jan 1999). In
> > > > > > > the paper, nonlocal wavefunction has 3 terms, one of which
> > > > > > > contains beta function, say W. The other two parts dont have any
> > > > > > > W in them, rather they are just plane wave solution. (Please have
> > > > > > > a look at equation 24 and 26 of the paper ). So, when we are
> > > > > > > doing z integration of nonlocal wavefunction with beta function
> > > > > > > W, we should have three terms, one of which should contain two W,
> > > > > > > but rest should just have one W. On the other hand in the code
> > > > > > > all three terms contain two beta functions!! (please have a look
> > > > > > > at line 228 of scatter_forw.f90). I am wondering if my
> > > > > > > understanding is right?
> > > > >
> > > > > Your understanding is wrong. On the line 228 you add to the integral
> > > > > ONLY contribution with two beta functions (from the 1st term in the
> > > > > nonlocal function, see Eq. 24) but on the line 393 the contribution
> > > > > from the 2nd term is added too. There is no 3rd term since every step
> > > > > you rotate your local solutions \psi_n in such a way that b_{\lambda
> > > > > \alpha lm} vanish (see the paragraph after Eq. 37).
> > > >
> > > > I believe that the equations 40, 41 and 42 implemented in the code
> > > > are in the momentum space. In the code, intw2 has 3 terms. We can tell
> > > > this by looking at the subroutine integrals.f90, where int2d is
> > > > defined. Now, by looking at the choi& Ihm 's paper, the very first term
> > > > of psi{alpha,l,m} has f{lambda,alpha,l,m}(equation26).And, if we
> > > > substitute this in equation 40, we should just get one term. I am just
> > > > confuesd on the fact that how come this one term in paper gets
> > > > transformed into 3 terms of the code!
> > >
> > > intw2(alpha,beta) is the integral of nonlocal solution (24) with w
> > > functions, intw2(alpha,beta) = \int_{0,d} w_{alpha}(r)*psi_{beta}(r)dr,
> > > where alpha,beta={alpha,l,m} in the paper. In each slab it will have TWO
> > > contributions from the first and second terms of (24), the one from the
> > > third term vanishes as I explained
[Pw_forum] possible bug in scatter_forw.f90
Dear Manoj
On Thursday 16 October 2008 23:15, Manoj Srivastava wrote:
> Dear Alexandar,
> Thank you very much. Your answers make sense and now i have better
> understanding of the subroutine scatter_forw.f90. I have one question
> about poten.f90 subroutine, where you calculate the V(p,gper) in each
> slices of the slab(equation 15). I have a question about Gz, which is
> 2*pi*q/L, with [-N/2]+1<=q>=[N/2]. Now in the code at the line at the line
> 60, you have Gz multiplied with bg(3,3). I kind of understand this is
> because 3rd direction is perpendicular to xy plane,
Exactly. As it is implemented now pwcond deals with systems
having monoclinic unit cell, i.e. such that a3 is perpendicular to both a1 and
a2 (a1 and a2 are not necessary orthogonal one to another) and the direction
of transport is a3. This seems to us the most general setup for transport and
I do not think we should consider at the moment the situation where the a3 is
not perpendicular to the xy plane.
Best regards,
Alexander
> but not totally clear
> about it. Would you mind explaining? my other question is when reciprocal
> space vectors b1, b2 and b3 are not orhogonal to each other, which is
> more general case, then should not we take bg(1,3) and bg(2,3) in there
> too?
> Thank you once again for listening to my questions and i hope i am
> not bothering you too much.
>
> Regards,
> Manoj Srivastava
> Physics Graduate Student
> Department of Physics
> Gainesville, FL, USA.
>
> have On Wed, 15 Oct 2008, Alexander wrote:
> > Dear Manoj
> >
> > On Tuesday 14 October 2008 17:49, Manoj Srivastava wrote:
> > > Dear Alexader,
> > >
> > > Thank you very much for your reply. I was out of town and could not
> > > see the message till yesterday. I have some questions on it, it would
> > > be great if you could answer them.
> > >
> > > On Fri, 10 Oct 2008, Alexander wrote:
> > > > Dear Manoj
> > > >
> > > > On Friday 10 October 2008 05:20, Manoj Srivastava wrote:
> > > > > Any follow ups on the message below? Alexander?
> > > > >
> > > > > Regards,
> > > > > Manoj
> > > > >
> > > > > On Wed, 8 Oct 2008, Manoj Srivastava wrote:
> > > > > > Dear All,
> > > > > > Is any body familiar with the scatter_forw.f90 subroutine of
> > > > > > PWCOND? I think there is a bug in this subroutine at the place
> > > > > > where you calculate intw2, which is z integration of nonlocal
> > > > > > wavefunction with beta function. I have looked up the necessary
> > > > > > formulae in the Choi & Ihm's paper (PRB 59, 2267, Jan 1999). In
> > > > > > the paper, nonlocal wavefunction has 3 terms, one of which
> > > > > > contains beta function, say W. The other two parts dont have any
> > > > > > W in them, rather they are just plane wave solution. (Please have
> > > > > > a look at equation 24 and 26 of the paper ). So, when we are
> > > > > > doing z integration of nonlocal wavefunction with beta function
> > > > > > W, we should have three terms, one of which should contain two W,
> > > > > > but rest should just have one W. On the other hand in the code
> > > > > > all three terms contain two beta functions!! (please have a look
> > > > > > at line 228 of scatter_forw.f90). I am wondering if my
> > > > > > understanding is right?
> > > >
> > > > Your understanding is wrong. On the line 228 you add to the integral
> > > > ONLY contribution with two beta functions (from the 1st term in the
> > > > nonlocal function, see Eq. 24) but on the line 393 the contribution
> > > > from the 2nd term is added too. There is no 3rd term since every step
> > > > you rotate your local solutions \psi_n in such a way that b_{\lambda
> > > > \alpha lm} vanish (see the paragraph after Eq. 37).
> > >
> > > I believe that the equations 40, 41 and 42 implemented in the code
> > > are in the momentum space. In the code, intw2 has 3 terms. We can tell
> > > this by looking at the subroutine integrals.f90, where int2d is
> > > defined. Now, by looking at the choi& Ihm 's paper, the very first term
> > > of psi{alpha,l,m} has f{lambda,alpha,l,m}(equation26).And, if we
> > > substitute this in equation 40, we should just get one term. I am just
> > > confuesd on the fact that how come this one term in paper gets
> > > transformed into 3 terms of the code!
> >
> > intw2(alpha,beta) is the integral of nonlocal solution (24) with w
> > functions, intw2(alpha,beta) = \int_{0,d} w_{alpha}(r)*psi_{beta}(r)dr,
> > where alpha,beta={alpha,l,m} in the paper. In each slab it will have TWO
> > contributions from the first and second terms of (24), the one from the
> > third term vanishes as I explained before. These two contributions are
> > calculated on the lines 228 and 393 of the code. The integrals intw1
> > (alpha,n)=\int_{0,d} w_{alpha}(r)*psi_{n}(r)dr are the integrals of local
> > solutions (17) with the same projector functions w.
> > The integrals intw2 and intw1 have nothing to do with boundary conditions
> > (40). They enter in (11) and are needed to construct the final
[Pw_forum] possible bug in scatter_forw.f90
Dear Alexandar,
Thank you very much. Your answers make sense and now i have better
understanding of the subroutine scatter_forw.f90. I have one question
about poten.f90 subroutine, where you calculate the V(p,gper) in each
slices of the slab(equation 15). I have a question about Gz, which is
2*pi*q/L, with [-N/2]+1<=q>=[N/2]. Now in the code at the line at the line
60, you have Gz multiplied with bg(3,3). I kind of understand this is
because 3rd direction is perpendicular to xy plane, but not totally clear
about it. Would you mind explaining? my other question is when reciprocal
space vectors b1, b2 and b3 are not orhogonal to each other, which is
more general case, then should not we take bg(1,3) and bg(2,3) in there
too?
Thank you once again for listening to my questions and i hope i am
not bothering you too much.
Regards,
Manoj Srivastava
Physics Graduate Student
Department of Physics
Gainesville, FL, USA.
have On Wed, 15 Oct 2008, Alexander wrote:
> Dear Manoj
>
> On Tuesday 14 October 2008 17:49, Manoj Srivastava wrote:
> > Dear Alexader,
> >
> > Thank you very much for your reply. I was out of town and could not see
> > the message till yesterday. I have some questions on it, it would be great
> > if you could answer them.
> >
> > On Fri, 10 Oct 2008, Alexander wrote:
> > > Dear Manoj
> > >
> > > On Friday 10 October 2008 05:20, Manoj Srivastava wrote:
> > > > Any follow ups on the message below? Alexander?
> > > >
> > > > Regards,
> > > > Manoj
> > > >
> > > > On Wed, 8 Oct 2008, Manoj Srivastava wrote:
> > > > > Dear All,
> > > > > Is any body familiar with the scatter_forw.f90 subroutine of PWCOND?
> > > > > I think there is a bug in this subroutine at the place where you
> > > > > calculate intw2, which is z integration of nonlocal wavefunction with
> > > > > beta function. I have looked up the necessary formulae in the Choi &
> > > > > Ihm's paper (PRB 59, 2267, Jan 1999). In the paper, nonlocal
> > > > > wavefunction has 3 terms, one of which contains beta function, say W.
> > > > > The other two parts dont have any W in them, rather they are just
> > > > > plane wave solution. (Please have a look at equation 24 and 26 of the
> > > > > paper ). So, when we are doing z integration of nonlocal wavefunction
> > > > > with beta function W, we should have three terms, one of which should
> > > > > contain two W, but rest should just have one W. On the other hand in
> > > > > the code all three terms contain two beta functions!! (please have a
> > > > > look at line 228 of scatter_forw.f90). I am wondering if my
> > > > > understanding is right?
> > >
> > > Your understanding is wrong. On the line 228 you add to the integral ONLY
> > > contribution with two beta functions (from the 1st term in the nonlocal
> > > function, see Eq. 24) but on the line 393 the contribution from the 2nd
> > > term is added too. There is no 3rd term since every step you rotate your
> > > local solutions \psi_n in such a way that b_{\lambda \alpha lm} vanish
> > > (see the paragraph after Eq. 37).
> >
> > I believe that the equations 40, 41 and 42 implemented in the code are
> > in the momentum space. In the code, intw2 has 3 terms. We can tell this by
> > looking at the subroutine integrals.f90, where int2d is defined. Now, by
> > looking at the choi& Ihm 's paper, the very first term of psi{alpha,l,m}
> > has f{lambda,alpha,l,m}(equation26).And, if we substitute this in equation
> > 40, we should just get one term. I am just confuesd on the fact that how
> > come this one term in paper gets transformed into 3 terms of the code!
>
> intw2(alpha,beta) is the integral of nonlocal solution (24) with w functions,
> intw2(alpha,beta) = \int_{0,d} w_{alpha}(r)*psi_{beta}(r)dr, where
> alpha,beta={alpha,l,m} in the paper. In each slab it will have TWO
> contributions from the first and second terms of (24), the one from the third
> term vanishes as I explained before. These two contributions are calculated
> on the lines 228 and 393 of the code. The integrals intw1
> (alpha,n)=\int_{0,d} w_{alpha}(r)*psi_{n}(r)dr are the integrals of local
> solutions (17) with the same projector functions w.
> The integrals intw2 and intw1 have nothing to do with boundary conditions
> (40). They enter in (11) and are needed to construct the final solutions
> according to Eq.(10). Substituting the form of this solution (10) in the
> boundary conditions (40) you will be led to the generalized eigenvalue
> problem, AX=exp(ikd) BX, with known matrices A and B and unknown
> coefficients X={a_n,C_{alpha,l,m}} defining the resulting solution (10).
>
> > Would you mind explaining? Also, the integrals that are defined in the
> > code are only in the slabs (nz1), so how are you taking the integration in
> > the region (0,d), which we need according to equations 40, 41 and 42 ?
>
> When you go over slabs you add new contributions to the integrals intw1 and
> intw2 (see the line 228 for the first contribution to intw2 and
[Pw_forum] possible bug in scatter_forw.f90
Dear Manoj
On Tuesday 14 October 2008 17:49, Manoj Srivastava wrote:
> Dear Alexader,
>
> Thank you very much for your reply. I was out of town and could not see
> the message till yesterday. I have some questions on it, it would be great
> if you could answer them.
>
> On Fri, 10 Oct 2008, Alexander wrote:
> > Dear Manoj
> >
> > On Friday 10 October 2008 05:20, Manoj Srivastava wrote:
> > > Any follow ups on the message below? Alexander?
> > >
> > > Regards,
> > > Manoj
> > >
> > > On Wed, 8 Oct 2008, Manoj Srivastava wrote:
> > > > Dear All,
> > > > Is any body familiar with the scatter_forw.f90 subroutine of PWCOND?
> > > > I think there is a bug in this subroutine at the place where you
> > > > calculate intw2, which is z integration of nonlocal wavefunction with
> > > > beta function. I have looked up the necessary formulae in the Choi &
> > > > Ihm's paper (PRB 59, 2267, Jan 1999). In the paper, nonlocal
> > > > wavefunction has 3 terms, one of which contains beta function, say W.
> > > > The other two parts dont have any W in them, rather they are just
> > > > plane wave solution. (Please have a look at equation 24 and 26 of the
> > > > paper ). So, when we are doing z integration of nonlocal wavefunction
> > > > with beta function W, we should have three terms, one of which should
> > > > contain two W, but rest should just have one W. On the other hand in
> > > > the code all three terms contain two beta functions!! (please have a
> > > > look at line 228 of scatter_forw.f90). I am wondering if my
> > > > understanding is right?
> >
> > Your understanding is wrong. On the line 228 you add to the integral ONLY
> > contribution with two beta functions (from the 1st term in the nonlocal
> > function, see Eq. 24) but on the line 393 the contribution from the 2nd
> > term is added too. There is no 3rd term since every step you rotate your
> > local solutions \psi_n in such a way that b_{\lambda \alpha lm} vanish
> > (see the paragraph after Eq. 37).
>
> I believe that the equations 40, 41 and 42 implemented in the code are
> in the momentum space. In the code, intw2 has 3 terms. We can tell this by
> looking at the subroutine integrals.f90, where int2d is defined. Now, by
> looking at the choi& Ihm 's paper, the very first term of psi{alpha,l,m}
> has f{lambda,alpha,l,m}(equation26).And, if we substitute this in equation
> 40, we should just get one term. I am just confuesd on the fact that how
> come this one term in paper gets transformed into 3 terms of the code!
intw2(alpha,beta) is the integral of nonlocal solution (24) with w functions,
intw2(alpha,beta) = \int_{0,d} w_{alpha}(r)*psi_{beta}(r)dr, where
alpha,beta={alpha,l,m} in the paper. In each slab it will have TWO
contributions from the first and second terms of (24), the one from the third
term vanishes as I explained before. These two contributions are calculated
on the lines 228 and 393 of the code. The integrals intw1
(alpha,n)=\int_{0,d} w_{alpha}(r)*psi_{n}(r)dr are the integrals of local
solutions (17) with the same projector functions w.
The integrals intw2 and intw1 have nothing to do with boundary conditions
(40). They enter in (11) and are needed to construct the final solutions
according to Eq.(10). Substituting the form of this solution (10) in the
boundary conditions (40) you will be led to the generalized eigenvalue
problem, AX=exp(ikd) BX, with known matrices A and B and unknown
coefficients X={a_n,C_{alpha,l,m}} defining the resulting solution (10).
> Would you mind explaining? Also, the integrals that are defined in the
> code are only in the slabs (nz1), so how are you taking the integration in
> the region (0,d), which we need according to equations 40, 41 and 42 ?
When you go over slabs you add new contributions to the integrals intw1 and
intw2 (see the line 228 for the first contribution to intw2 and the part "add
to the integrals" for another contribution to intw2 and contributions to
intw1) so at the end you obtain integrals over all the region.
Regards,
Alexander
>
> > > > I have one more question in the later part of the same subroutine.
> > > > What
> > > >
> > > > does the lapack subroutine
> > > > ZGESV(2*n2d,2*n2d+norb*npol,amat,2*n2d,ipiv,xmat,2*n2d,info)
> > > > do?
> > > > I tried to look it up and i got the idea that it is trying to solve
> > > > amat*x=xmat, with amat and xmat known and x unknown, and at the end
> > > > of calculation it stores x in xmat.
> > > > so, basically it does-- x=[(amat)^(-1)]*xmat. Am i right? So, it
> > > > changes the structure of xmat from what is defined in 'constructs
> > > > matrices' part. Is it correct?
> >
> > Here, you are right.
> >
> > > > Also, afterwards in this code where it 'rotates integrals' is not
> > > > very clear to me.
> > > > Could somebody please tell me in little detail, what is going on
> > > > here?
> >
> > As I explained before rotation means that every step (at each slab)
> > you make a linear combination of local solutions
[Pw_forum] possible bug in scatter_forw.f90
Dear Alexader,
Thank you very much for your reply. I was out of town and could not see
the message till yesterday. I have some questions on it, it would be great
if you could answer them.
On Fri, 10 Oct 2008, Alexander wrote:
> Dear Manoj
>
> On Friday 10 October 2008 05:20, Manoj Srivastava wrote:
> > Any follow ups on the message below? Alexander?
> >
> > Regards,
> > Manoj
> >
> > On Wed, 8 Oct 2008, Manoj Srivastava wrote:
> > > Dear All,
> > > Is any body familiar with the scatter_forw.f90 subroutine of PWCOND? I
> > > think there is a bug in this subroutine at the place where you calculate
> > > intw2, which is z integration of nonlocal wavefunction with beta
> > > function. I have looked up the necessary formulae in the Choi & Ihm's
> > > paper (PRB 59, 2267, Jan 1999). In the paper, nonlocal wavefunction has 3
> > > terms, one of which contains beta function, say W. The other two parts
> > > dont have any W in them, rather they are just plane wave solution.
> > > (Please have a look at equation 24 and 26 of the paper ). So, when we are
> > > doing z integration of nonlocal wavefunction with beta function W, we
> > > should have three terms, one of which should contain two W, but rest
> > > should just have one W. On the other hand in the code all three terms
> > > contain two beta functions!! (please have a look at line 228 of
> > > scatter_forw.f90). I am wondering if my understanding is right?
>
> Your understanding is wrong. On the line 228 you add to the integral ONLY
> contribution with two beta functions (from the 1st term in the nonlocal
> function, see Eq. 24) but on the line 393 the contribution from the 2nd term
> is added too. There is no 3rd term since every step you rotate your local
> solutions \psi_n in such a way that b_{\lambda \alpha lm} vanish (see the
> paragraph after Eq. 37).
I believe that the equations 40, 41 and 42 implemented in the code are
in the momentum space. In the code, intw2 has 3 terms. We can tell this by
looking at the subroutine integrals.f90, where int2d is defined. Now, by
looking at the choi& Ihm 's paper, the very first term of psi{alpha,l,m}
has f{lambda,alpha,l,m}(equation26).And, if we substitute this in equation
40, we should just get one term. I am just confuesd on the fact that how
come this one term in paper gets transformed into 3 terms of the code!
Would you mind explaining? Also, the integrals that are defined in the
code are only in the slabs (nz1), so how are you taking the integration in
the region (0,d), which we need according to equations 40, 41 and 42 ?
>
> > > I have one more question in the later part of the same subroutine. What
> > > does the lapack subroutine
> > > ZGESV(2*n2d,2*n2d+norb*npol,amat,2*n2d,ipiv,xmat,2*n2d,info)
> > > do?
> > > I tried to look it up and i got the idea that it is trying to solve
> > > amat*x=xmat, with amat and xmat known and x unknown, and at the end of
> > > calculation it stores x in xmat.
> > > so, basically it does-- x=[(amat)^(-1)]*xmat. Am i right? So, it changes
> > > the structure of xmat from what is defined in 'constructs matrices'
> > > part. Is it correct?
>
> Here, you are right.
>
> > > Also, afterwards in this code where it 'rotates integrals' is not very
> > > clear to me.
> > > Could somebody please tell me in little detail, what is going on
> > > here?
> As I explained before rotation means that every step (at each slab)
> you make a linear combination of local solutions \psi_n with the
> transformation matrix h_{nn'} (see the last paragraph on the p. 2270).
> so that the new solutions have the property:
> b_{\lambda n} = \delta_{\lambda n} and the new nonlocal solutions have
> b_{\lambda \alpha lm}=0. Doing this transformation of local and nonlocal
> solutions you should also perform the corresponding transformations
> of the integrals.
>
> > > Also, is this subroutine written just on the basis of Choi and Ihm
> > > paper, or are there more reference to it? If yes, would someone mind
> > > mentioning them?
> Unfortunately, the paper of Choi and Ihm is very detail, and in the
> PWCOND code we followed it very closely, so no more references
> are needed. In our papers we just extended those ideas to ultrasoft
> pseudopotentials, magnetism, spin-orbit coupling and so on.
>
> Hope this helped you,
> regards, Alexander
>
> > >
> > > Regards,
> > > Manoj Srivastava
> > > Physics Graduate Student
> > > University of Florida,
> > > Gainesville,FL, USA
> >
> > ___
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
Once again thank you very much for your help. I appreciate it.
Regards,
Manoj Srivastava
[Pw_forum] possible bug in scatter_forw.f90
Dear Manoj
On Friday 10 October 2008 05:20, Manoj Srivastava wrote:
> Any follow ups on the message below? Alexander?
>
> Regards,
> Manoj
>
> On Wed, 8 Oct 2008, Manoj Srivastava wrote:
> > Dear All,
> > Is any body familiar with the scatter_forw.f90 subroutine of PWCOND? I
> > think there is a bug in this subroutine at the place where you calculate
> > intw2, which is z integration of nonlocal wavefunction with beta
> > function. I have looked up the necessary formulae in the Choi & Ihm's
> > paper (PRB 59, 2267, Jan 1999). In the paper, nonlocal wavefunction has 3
> > terms, one of which contains beta function, say W. The other two parts
> > dont have any W in them, rather they are just plane wave solution.
> > (Please have a look at equation 24 and 26 of the paper ). So, when we are
> > doing z integration of nonlocal wavefunction with beta function W, we
> > should have three terms, one of which should contain two W, but rest
> > should just have one W. On the other hand in the code all three terms
> > contain two beta functions!! (please have a look at line 228 of
> > scatter_forw.f90). I am wondering if my understanding is right?
Your understanding is wrong. On the line 228 you add to the integral ONLY
contribution with two beta functions (from the 1st term in the nonlocal
function, see Eq. 24) but on the line 393 the contribution from the 2nd term
is added too. There is no 3rd term since every step you rotate your local
solutions \psi_n in such a way that b_{\lambda \alpha lm} vanish (see the
paragraph after Eq. 37).
> > I have one more question in the later part of the same subroutine. What
> > does the lapack subroutine
> > ZGESV(2*n2d,2*n2d+norb*npol,amat,2*n2d,ipiv,xmat,2*n2d,info)
> > do?
> > I tried to look it up and i got the idea that it is trying to solve
> > amat*x=xmat, with amat and xmat known and x unknown, and at the end of
> > calculation it stores x in xmat.
> > so, basically it does-- x=[(amat)^(-1)]*xmat. Am i right? So, it changes
> > the structure of xmat from what is defined in 'constructs matrices'
> > part. Is it correct?
Here, you are right.
> > Also, afterwards in this code where it 'rotates integrals' is not very
> > clear to me.
> > Could somebody please tell me in little detail, what is going on
> > here?
As I explained before rotation means that every step (at each slab)
you make a linear combination of local solutions \psi_n with the
transformation matrix h_{nn'} (see the last paragraph on the p. 2270).
so that the new solutions have the property:
b_{\lambda n} = \delta_{\lambda n} and the new nonlocal solutions have
b_{\lambda \alpha lm}=0. Doing this transformation of local and nonlocal
solutions you should also perform the corresponding transformations
of the integrals.
> > Also, is this subroutine written just on the basis of Choi and Ihm
> > paper, or are there more reference to it? If yes, would someone mind
> > mentioning them?
Unfortunately, the paper of Choi and Ihm is very detail, and in the
PWCOND code we followed it very closely, so no more references
are needed. In our papers we just extended those ideas to ultrasoft
pseudopotentials, magnetism, spin-orbit coupling and so on.
Hope this helped you,
regards, Alexander
> >
> > Regards,
> > Manoj Srivastava
> > Physics Graduate Student
> > University of Florida,
> > Gainesville,FL, USA
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
[Pw_forum] possible bug in scatter_forw.f90
Any follow ups on the message below? Alexander? Regards, Manoj On Wed, 8 Oct 2008, Manoj Srivastava wrote: > > Dear All, > Is any body familiar with the scatter_forw.f90 subroutine of PWCOND? I > think there is a bug in this subroutine at the place where you calculate > intw2, which is z integration of nonlocal wavefunction with beta function. > I have looked up the necessary formulae in the Choi & Ihm's paper (PRB 59, > 2267, Jan 1999). In the paper, nonlocal wavefunction has 3 terms, one of > which contains beta function, say W. The other two parts dont have any W > in them, rather they are just plane wave solution. (Please have a look at > equation 24 and 26 of the paper ). So, when we are doing z integration of > nonlocal wavefunction with beta function W, we should have three terms, > one of which should contain two W, but rest should just have one W. On the > other hand in the code all three terms contain two beta functions!! > (please have a look at line 228 of scatter_forw.f90). I am wondering if my > understanding is right? > I have one more question in the later part of the same subroutine. What > does the lapack subroutine > ZGESV(2*n2d,2*n2d+norb*npol,amat,2*n2d,ipiv,xmat,2*n2d,info) > do? > I tried to look it up and i got the idea that it is trying to solve > amat*x=xmat, with amat and xmat known and x unknown, and at the end of > calculation it stores x in xmat. > so, basically it does-- x=[(amat)^(-1)]*xmat. Am i right? So, it changes > the structure of xmat from what is defined in 'constructs matrices' > part. Is it correct? > Also, afterwards in this code where it 'rotates integrals' is not very > clear to me. > Could somebody please tell me in little detail, what is going on > here? Also, is this subroutine written just on the basis of Choi and Ihm > paper, or are there more reference to it? If yes, would someone mind > mentioning them? > > Regards, > Manoj Srivastava > Physics Graduate Student > University of Florida, > Gainesville,FL, USA > >
[Pw_forum] possible bug in scatter_forw.f90
Dear All, Is any body familiar with the scatter_forw.f90 subroutine of PWCOND? I think there is a bug in this subroutine at the place where you calculate intw2, which is z integration of nonlocal wavefunction with beta function. I have looked up the necessary formulae in the Choi & Ihm's paper (PRB 59, 2267, Jan 1999). In the paper, nonlocal wavefunction has 3 terms, one of which contains beta function, say W. The other two parts dont have any W in them, rather they are just plane wave solution. (Please have a look at equation 24 and 26 of the paper ). So, when we are doing z integration of nonlocal wavefunction with beta function W, we should have three terms, one of which should contain two W, but rest should just have one W. On the other hand in the code all three terms contain two beta functions!! (please have a look at line 228 of scatter_forw.f90). I am wondering if my understanding is right? I have one more question in the later part of the same subroutine. What does the lapack subroutine ZGESV(2*n2d,2*n2d+norb*npol,amat,2*n2d,ipiv,xmat,2*n2d,info) do? I tried to look it up and i got the idea that it is trying to solve amat*x=xmat, with amat and xmat known and x unknown, and at the end of calculation it stores x in xmat. so, basically it does-- x=[(amat)^(-1)]*xmat. Am i right? So, it changes the structure of xmat from what is defined in 'constructs matrices' part. Is it correct? Also, afterwards in this code where it 'rotates integrals' is not very clear to me. Could somebody please tell me in little detail, what is going on here? Also, is this subroutine written just on the basis of Choi and Ihm paper, or are there more reference to it? If yes, would someone mind mentioning them? Regards, Manoj Srivastava Physics Graduate Student University of Florida, Gainesville,FL, USA
