Hi, according to the wien2k web page
http://www.wien2k.at/reg_user/limitations/ calculation of forces with spin-orbit is not yet implemented. On 07/08/12 16:05, Alexey Korshunov wrote: > Prof. Blaha and wien users. > > I am running wien version 11.1 on a intel core i7 machine with > Mandriva 2010 operating system, fortran compiler ifort 11.1 and math > libraries mkl 10. > The purpose of my calculations is to get forces to perfom surface > structure relaxation. > I am calculating tungsten slab with the following initial structure > > W_surface > CXY LATTICE,NONEQUIV.ATOMS: > 765_Cmmm > MODE OF CALC=RELA > unit=bohr > 5.981401 8.458979 84.589790 90.000000 90.000000 > 90.000000 > ATOM -1: X=0.00000000 Y=0.00000000 Z=0.00000000 > MULT= 1 ISPLIT= 8 > W 1 NPT= 781 R0=0.00000500 RMT= 2.2000 Z: > 74.0 > LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 > 0.0000000 1.0000000 0.0000000 > 0.0000000 0.0000000 1.0000000 > ATOM -2: X=0.50000000 Y=0.00000000 Z=0.05000000 > MULT= 2 ISPLIT= 8 > -2: X=0.50000000 Y=0.00000000 Z=0.95000000 > W 2 NPT= 781 R0=0.00000500 RMT= 2.2000 Z: > 74.0 > LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 > 0.0000000 1.0000000 0.0000000 > 0.0000000 0.0000000 1.0000000 > ATOM -3: X=0.00000000 Y=0.00000000 Z=0.10000000 > MULT= 2 ISPLIT= 8 > -3: X=0.00000000 Y=0.00000000 Z=0.90000000 > W 3 NPT= 781 R0=0.00000500 RMT= 2.2000 Z: > 74.0 > LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 > 0.0000000 1.0000000 0.0000000 > 0.0000000 0.0000000 1.0000000 > ATOM -4: X=0.50000000 Y=0.00000000 Z=0.15000000 > MULT= 2 ISPLIT= 8 > -4: X=0.50000000 Y=0.00000000 Z=0.85000000 > W 4 NPT= 781 R0=0.00000500 RMT= 2.2000 Z: > 74.0 > LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 > 0.0000000 1.0000000 0.0000000 > 0.0000000 0.0000000 1.0000000 > ATOM -5: X=0.00000000 Y=0.00000000 Z=0.20000000 > MULT= 2 ISPLIT= 8 > -5: X=0.00000000 Y=0.00000000 Z=0.80000000 > W 5 NPT= 781 R0=0.00000500 RMT= 2.2000 Z: > 74.0 > LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 > 0.0000000 1.0000000 0.0000000 > 0.0000000 0.0000000 1.0000000 > ATOM -6: X=0.50000000 Y=0.00000000 Z=0.25000000 > MULT= 2 ISPLIT= 8 > -6: X=0.50000000 Y=0.00000000 Z=0.75000000 > W 6 NPT= 781 R0=0.00000500 RMT= 2.2000 Z: > 74.0 > LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 > 0.0000000 1.0000000 0.0000000 > 0.0000000 0.0000000 1.0000000 > ATOM -7: X=0.00000000 Y=0.00000000 Z=0.30000000 > MULT= 2 ISPLIT= 8 > -7: X=0.00000000 Y=0.00000000 Z=0.70000000 > W 7 NPT= 781 R0=0.00000500 RMT= 2.2000 Z: > 74.0 > LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 > 0.0000000 1.0000000 0.0000000 > 0.0000000 0.0000000 1.0000000 > 8 NUMBER OF SYMMETRY OPERATIONS > > using GGA PBE XC potential, spin-orbit interaction without spin > polarization, RKmax=7, k-mesh=2000. > The commandline is run_lapw -p -so -cc 0.00001 -ec 0.0001 -fc 1.0 -i > 120 -r 20. > There is the force result of last two iterations: > > :ITE069: 69. ITERATION TOTAL FORCE WITH RESPECT TO THE GLOBAL > COORDINATE SYSTEM: > :FGL001: 1.ATOM 0.000000000 0.000000000 > 0.000000000 partial forces > :FGL002: 2.ATOM 0.000000000 0.000000000 > 3.035000000 partial forces > :FGL003: 3.ATOM 0.000000000 0.000000000 > 2.956000000 partial forces > :FGL004: 4.ATOM 0.000000000 0.000000000 > 16.247000000 partial forces > :FGL005: 5.ATOM 0.000000000 0.000000000 > 79.306000000 partial forces > :FGL006: 6.ATOM 0.000000000 0.000000000 > 5.081000000 partial forces > :FGL007: 7.ATOM 0.000000000 0.000000000 > 828.277000000 partial forces > > :ITE070: 70. ITERATION TOTAL FORCE WITH RESPECT TO THE GLOBAL > COORDINATE SYSTEM: > :FGL001: 1.ATOM 0.000000000 0.000000000 > 0.000000000 total forces > :FGL002: 2.ATOM 0.000000000 0.000000000 > 289.947000000 total forces > :FGL003: 3.ATOM 0.000000000 0.000000000 > 123.015000000 total forces > :FGL004: 4.ATOM 0.000000000 0.000000000 > 72.397000000 total forces > :FGL005: 5.ATOM 0.000000000 0.000000000 > 33.811000000 total forces > :FGL006: 6.ATOM 0.000000000 0.000000000 > 25.803000000 total forces > :FGL007: 7.ATOM 0.000000000 0.000000000 > -56.857000000 total forces > > The difference is because of appearance of huge valence forces in last > iteration: > > VALENCE-FORCE IN mRy/a.u. = |F| Fx Fy Fz > :FVA001: 1.ATOM 0.000 0.000 0.000 > 0.000 > VALENCE-FORCE IN mRy/a.u. = |F| Fx Fy Fz > :FVA002: 2.ATOM 287.029 0.000 0.000 > 287.029 > VALENCE-FORCE IN mRy/a.u. = |F| Fx Fy Fz > :FVA003: 3.ATOM 119.172 0.000 0.000 > 119.172 > VALENCE-FORCE IN mRy/a.u. = |F| Fx Fy Fz > :FVA004: 4.ATOM 55.430 0.000 0.000 > 55.430 > VALENCE-FORCE IN mRy/a.u. = |F| Fx Fy Fz > :FVA005: 5.ATOM 51.852 0.000 0.000 > -51.852 > VALENCE-FORCE IN mRy/a.u. = |F| Fx Fy Fz > :FVA006: 6.ATOM 29.373 0.000 0.000 > 29.373 > VALENCE-FORCE IN mRy/a.u. = |F| Fx Fy Fz > :FVA007: 7.ATOM 684.540 0.000 0.000 > -684.540 > > The total forces in the 70-th iteration look unphysical. A very high > force has appeared on the next to the internal layer of the slab > (it is the 6-th layer from the surface). > This leads to an icrease of interlayer distance between internal > monolayers. On the other hand, the total forces in the 69-th iteration are > rather realistic. However, they do not contain the valence-force > corrections. > This effect appears only in the spin-orbit mode. > > The questions are: > 1. Is it possible to use the forces without valence-force corrections, > e.g. pure HELLMAN-FEYMAN forces, for the relaxation? > > 2. Can the spin-orbit mode lead to the wrong forces? > > Sincerely, Korshunov Alexey, Sarov State Physical Tecnical Institute, > Russia. > al.korshunof at gmail.com <mailto:al.korshunof at gmail.com> > > > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien