Hello,
I'm trying to get the HOMO LUMO orbital energies by using the pspw module. By setting "set nwpw:excited_ne 1 0" I think the LUMO orbital should be calculated. However, when I print out the orbital energies, the virtual orbital energy is much lower than the occupied orbitals. Then, I am confused. Can someone tell me what's wrong with my calculation?
My input is:
start pbe
charge 0.0
permanent_dir ./perm
scratch_dir ./tmp
geometry units angstroms
C 9.141526 8.845225 4.865224
C 10.562604 8.619441 4.887125
C 11.436824 9.663112 4.892389
C 10.965554 11.022710 4.874442
C 9.544353 11.248537 4.860464
C 8.670122 10.204881 4.856862
C 11.864753 12.096035 4.868009
C 13.268859 11.890784 4.882397
C 11.416386 13.442191 4.842983
N 11.033836 14.548173 4.820549
N 14.425017 11.708542 4.894561
C 8.242482 7.771817 4.849752
C 6.838526 7.977373 4.828185
C 8.690670 6.425357 4.850905
N 5.682506 8.159980 4.810314
N 9.072755 5.318984 4.850357
H 10.933340 7.589931 4.898385
H 12.515334 9.478534 4.908115
H 9.173573 12.278066 4.851729
H 7.591581 10.389528 4.845351
end
nwpw
simulation_cell
boundary_conditions aperiodic
end
#virtual 1
cutoff 20.0
xc pbe96
lmbfgs
pseudopotentials
* library paw_default
end
end
set nwpw:excited_ne 1 0
task pspw energy
And the output orbital energies are:
orbital energies:
-0.2580606E+00 ( -7.022eV)
-0.3059743E+00 ( -8.326eV)
-0.3222919E+00 ( -8.770eV)
-0.3325314E+00 ( -9.049eV)
-0.3353264E+00 ( -9.125eV)
-0.3426305E+00 ( -9.324eV)
-0.3444889E+00 ( -9.374eV)
-0.3478232E+00 ( -9.465eV)
-0.3482071E+00 ( -9.475eV)
-0.3485748E+00 ( -9.485eV)
-0.3491926E+00 ( -9.502eV)
-0.3547385E+00 ( -9.653eV)
-0.3582714E+00 ( -9.749eV)
-0.3636249E+00 ( -9.895eV)
-0.3774640E+00 ( -10.271eV)
-0.4029751E+00 ( -10.966eV)
-0.4160299E+00 ( -11.321eV)
-0.4337441E+00 ( -11.803eV)
-0.4399846E+00 ( -11.973eV)
-0.4504432E+00 ( -12.257eV)
-0.4539936E+00 ( -12.354eV)
-0.5141779E+00 ( -13.992eV)
-0.5440174E+00 ( -14.804eV)
-0.5441582E+00 ( -14.807eV)
-0.5803513E+00 ( -15.792eV)
-0.6169718E+00 ( -16.789eV)
-0.6293742E+00 ( -17.126eV)
-0.6987671E+00 ( -19.015eV)
-0.7489697E+00 ( -20.381eV)
-0.7663552E+00 ( -20.854eV)
-0.8107413E+00 ( -22.062eV)
-0.8517569E+00 ( -23.178eV)
-0.8573442E+00 ( -23.330eV)
-0.8575380E+00 ( -23.335eV)
-0.8770616E+00 ( -23.866eV)
-0.8833622E+00 ( -24.038eV)
virtual orbital energies:
-0.1987759E+01 ( -54.090eV)
Also I have another question. For periodic boundary calculations in pspw, what's the reference energy for the ouput orbital energy? I mean what's the vacuum level. Since for aperodic calculation in pspw, I think the vacuum energy is 0, the output orbital energy is the true energy assuming the vacuum level is 0. So what about periodic calculations?
Best,
Xiaoming Wang
Postdoc
Rutgers University
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