From the energy part of the output alone we can't tell if the input was
correct. You see a smallish difference and lower energy with the ghost, which
one would expect.
Total energies are meaningless, and of course adding a few basis functions won't
change the total by a lot. You need to compare differences (like a binding
energy, as you indicated in your original post).
In the example outputs below, the difference (in absolute energies) is 0.09 eV.
That's 2 kcal/mol or 9 kJ/mol. Depending on the interaction you are looking at,
this may or may not be negligible.
Herbert
On 03/18/2011 02:00 AM, Wei Hu wrote:
Dear,the ghost atoms calculations seem to little effects on the total energy
from my results. Is there any wrong?
My results about a nitrogen-vacancy center in bulk diamond C62N (2*2*2):
The results with ghost atoms:
siesta: Program's energy decomposition (eV):
siesta: Eions = 16680.576136
siesta: Ena = 3653.202863
siesta: Ekin = 7163.588024
siesta: Enl = -820.400928
siesta: DEna = -182.458272
siesta: DUscf = 15.575306
siesta: DUext = 0.000000
siesta: Exc = -3054.613637
siesta: eta*DQ = 0.000000
siesta: Emadel = 0.000000
siesta: Ekinion = 0.000000
siesta: Eharris = -9905.679557
siesta: Etot = -9905.682781
siesta: FreeEng = -9905.682783
siesta: Final energy (eV):
siesta: Kinetic = 7163.588024
siesta: Hartree = 894.608032
siesta: Ext. field = 0.000000
siesta: Exch.-corr. = -3054.613637
siesta: Ion-electron = -8393.758885
siesta: Ion-ion = -6515.506314
siesta: Ekinion = 0.000000
siesta: Total = -9905.682781
The results without ghost atoms:
siesta: Program's energy decomposition (eV):
siesta: Eions = 16680.576136
siesta: Ena = 3653.202863
siesta: Ekin = 7164.385562
siesta: Enl = -820.554764
siesta: DEna = -182.943454
siesta: DUscf = 15.589130
siesta: DUext = 0.000000
siesta: Exc = -3054.694636
siesta: eta*DQ = 0.000000
siesta: Emadel = 0.000000
siesta: Ekinion = 0.000000
siesta: Eharris = -9905.587400
siesta: Etot = -9905.591435
siesta: FreeEng = -9905.591437
siesta: Final energy (eV):
siesta: Kinetic = 7164.385562
siesta: Hartree = 894.861106
siesta: Ext. field = 0.000000
siesta: Exch.-corr. = -3054.694636
siesta: Ion-electron = -8394.637153
siesta: Ion-ion = -6515.506314
siesta: Ekinion = 0.000000
siesta: Total = -9905.591435
-----Original E-mail-----
From: "Herbert Fruchtl"<herbert.fruc...@st-andrews.ac.uk>
Sent Time: 2011-3-17 22:36:53
To: siesta-l@uam.es
Cc:
Subject: Re: [SIESTA-L] about basis-set superposition error (BSSE)
You can calculate counterpoise-corrected energies by specifying ghost atoms.
There is no way of doing counterpoise-corrected geometry optimisations in
SIESTA.
Herbert
On 03/17/2011 01:57 PM, yf liu wrote:
Hello everybody,
whether the basis-set superposition error (BSSE) is included in siesta
calculation. when i calculate the molecule adsorption on carbon nanotube, i
found the adsorption energy is some higher than the well know value. how can i
add the BSSE in siesta calculation?
yours
yufeng liu
--
Herbert Fruchtl
Senior Scientific Computing Officer
School of Chemistry, School of Mathematics and Statistics
University of St Andrews
--
The University of St Andrews is a charity registered in Scotland:
No SC013532
--
Herbert Fruchtl
Senior Scientific Computing Officer
School of Chemistry, School of Mathematics and Statistics
University of St Andrews
--
The University of St Andrews is a charity registered in Scotland:
No SC013532
