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modified on 8 March 2011 at 15:16 ••• 6,760 views

# NWPW DEVLOPMENT BLOG

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### Notes on Current NWPW Devlopoments

December 21, 2010 (EJB): I just checked in some changes to the development tree that makes it easier to define antiferromagnetic structures. Basically a scaling factor was added to the to the non-local psp for up/down spins on atoms and angular momentum that you specify. The nwpw input block

The pseudopotential energy

$E_{psp}= \sum_{\sigma=\uparrow,\downarrow} \sum_{i=1}^{n_{elc}^\sigma} \sum_{I=1}^{n_{ions}} \left( <\psi_i^\sigma|V_{local}^{I}|\psi_i^\sigma> + \sum_{l=0}^{l_{max}^I} \sum_{m=-l}^{l} \sum_{n=1}^{n_{max}^I} \sum_{n'=1}^{n_{max}^I} <\psi_i^\sigma|P_{nlm}^I> h_{l,n,n'}^I \right)$

was modified to

$E_{psp}= \sum_{\sigma=\uparrow,\downarrow} \sum_{i=1}^{n_{elc}^\sigma} \sum_{I=1}^{n_{ions}} \left( <\psi_i^\sigma|V_{local}^{I}|\psi_i^\sigma> + \sum_{l=0}^{l_{max}^I} \sum_{m=-l}^{l} \sum_{n=1}^{n_{max}^I} \sum_{n'=1}^{n_{max}^I} \left(1-\delta_{l,l^\sigma} \delta_{I,ionlist^\sigma}(\xi^\sigma-1)\right) <\psi_i^\sigma|P_{nlm}^I> h_{l,n,n'}^I \right)$

An example input is as follows:

title "hematite 10 atoms"

start hema10

memory 1900 mb

permanent_dir ./perm
scratch_dir   ./perm

geometry center noautosym noautoz print
system crystal
lat_a 5.42
lat_b 5.42
lat_c 5.42
alpha 55.36
beta  55.36
gamma 55.36
end
Fe                  0.355000   0.355000   0.355000
Fe                  0.145000   0.145000   0.145000
Fe                 -0.355000  -0.355000  -0.355000
Fe                  0.855000   0.855000   0.855000
O                   0.550000  -0.050000   0.250000
O                   0.250000   0.550000  -0.050000
O                  -0.050000   0.250000   0.550000
O                  -0.550000   0.050000  -0.250000
O                  -0.250000  -0.550000   0.050000
O                   0.050000  -0.250000  -0.550000
end

nwpw
virtual 8
odft
ewald_rcut 3.0
ewald_ncut 8
xc pbe96
lmbfgs
cutoff 10.0
mult 1
dplot
density diff diff1.cube
end

#spin penalty functions
pspspin up   d -1.0 1:2
pspspin down d -1.0 3:4
end
task pspw energy
task pspw pspw_dplot

nwpw
pspspin off
dplot
density diff diff2.cube
end
end
task pspw energy
task pspw pspw_dplot