dipole correction for charged defect. How?
Posted: Mon Jun 29, 2009 10:43 pm
I read the manual and is confused with the process of dipole correction. So below i list what i have done, and hope someone can tell me what to do.
1. calculate total energy, let's call it E1, (=-.96258487E+03) of the neutral host (defect free, cubic) without dipole correction.
2. calculate total energy E2 (=-.41435225E+03) of the neutral host (defect free, same as above) with dipole correction (IDIPOL = 4 and DIPOL = 0.5 0.5 0.5). For this calculation, the OUTCAR gives the following:
DIPCOR: dipole corrections for dipol
direction 1 min pos 1, direction 2 min pos 1, direction 3 min pos 1,
dipolmoment 53.303268 95.807282 -98.181446 electrons x Angstroem
Tr[quadrupol] -2121.281495
energy correction for charged system 0.000000 eV
dipol+quadrupol energy correction 548.432781 eV
added-field ion interaction 0.000000 eV (added to PSCEN)
3. calculate total energy E3 (=-.93008844E+03) of the defective host (with a 4- charged vacancy) without correction, i.e., just specify number of NELECT.
4. calculate total energy E4 (=-.43049393E+03) of the above defective host with dipole correction (settings same as in step 2). For this calculation, the OUTCAR gives the following:
DIPCOR: dipole corrections for dipol
direction 1 min pos 1, direction 2 min pos 1, direction 3 min pos 1,
dipolmoment 56.214933 17.202532 -85.830147 electrons x Angstroem
Tr[quadrupol] -1922.380306
energy correction for charged system 30.835079 eV
dipol+quadrupol energy correction 468.765048 eV
added-field ion interaction 0.000000 eV (added to PSCEN)
Now suppose the chemical potential of the vacancy element is mu, dielectric constant is k, and Fermi level is at valence band maximum. How should I calculate the formation energy?
The manual http://cms.mpi.univie.ac.at/vasp/vasp/n ... car-dipol2 says "If no dipole-dipole interaction is present you can now simply scale down the energy printed on the line "dipol+quadrupol energy correction ..." of file OUTCAR by the ratio "defect-induced quadrupole/total cell quadrupole" since this interaction is proportional to the quadrupole moment." How to confirm there is no dipole-dipole interaction?
1. calculate total energy, let's call it E1, (=-.96258487E+03) of the neutral host (defect free, cubic) without dipole correction.
2. calculate total energy E2 (=-.41435225E+03) of the neutral host (defect free, same as above) with dipole correction (IDIPOL = 4 and DIPOL = 0.5 0.5 0.5). For this calculation, the OUTCAR gives the following:
DIPCOR: dipole corrections for dipol
direction 1 min pos 1, direction 2 min pos 1, direction 3 min pos 1,
dipolmoment 53.303268 95.807282 -98.181446 electrons x Angstroem
Tr[quadrupol] -2121.281495
energy correction for charged system 0.000000 eV
dipol+quadrupol energy correction 548.432781 eV
added-field ion interaction 0.000000 eV (added to PSCEN)
3. calculate total energy E3 (=-.93008844E+03) of the defective host (with a 4- charged vacancy) without correction, i.e., just specify number of NELECT.
4. calculate total energy E4 (=-.43049393E+03) of the above defective host with dipole correction (settings same as in step 2). For this calculation, the OUTCAR gives the following:
DIPCOR: dipole corrections for dipol
direction 1 min pos 1, direction 2 min pos 1, direction 3 min pos 1,
dipolmoment 56.214933 17.202532 -85.830147 electrons x Angstroem
Tr[quadrupol] -1922.380306
energy correction for charged system 30.835079 eV
dipol+quadrupol energy correction 468.765048 eV
added-field ion interaction 0.000000 eV (added to PSCEN)
Now suppose the chemical potential of the vacancy element is mu, dielectric constant is k, and Fermi level is at valence band maximum. How should I calculate the formation energy?
The manual http://cms.mpi.univie.ac.at/vasp/vasp/n ... car-dipol2 says "If no dipole-dipole interaction is present you can now simply scale down the energy printed on the line "dipol+quadrupol energy correction ..." of file OUTCAR by the ratio "defect-induced quadrupole/total cell quadrupole" since this interaction is proportional to the quadrupole moment." How to confirm there is no dipole-dipole interaction?