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<DIV><FONT face=Arial size=2>Hi,</FONT></DIV>
<DIV><FONT face=Arial size=2>I want to modifiy the Hartree exchange potential to
take into account a screened coulomb potential. Which files need to be altered?
I noticed that a subroutine hartree(..) is called but couldn't find
it.</FONT></DIV>
<DIV><FONT face=Arial size=2>Also I wanted to change the exchange functional for
a new functional.</FONT></DIV>
<DIV><FONT face=Arial size=2>I changed Modules/functionals.f90 to call a new
functional, iexch=8,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> ELSEIF (iexch == 8)
THEN !
'bnl'<BR> CALL slater_bnl(rs, ex, vx)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> and then added the new functional in
flib/functionals.f90 as a new subroutine under the slater one. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial
size=2>!!-----------------------------------------------------------------------<BR>subroutine
slater_bnl (rs, ex, vx)<BR>
!-----------------------------------------------------------------------<BR>
! bnl<BR> !<BR> USE
kinds<BR> implicit none<BR> real(DP) :: rs, ex, vx, kf, q<BR>
real(DP), parameter :: f= -0.687247939924714d0, alpha = 2.0d0/3.0d0,
&<BR> pi34
= 0.6203504908994d0, pie=3.141592653589793d0 ,gam=0.5d0 <BR> !
pi34=(3/4pi)^(1/3)<BR> ! f = -9/8*(3/2pi)^(2/3)<BR>
!<BR> kf=3d0*pie**2*pi34/rs<BR> q=gam/kf<BR>
<BR> ex=(kf/(2d0*pie))*(q**2*(((2d0*dsqrt(pie)/q)*derf(1d0/q))-1d0+
&<BR> ((q**2-2d0)*(1d0-dexp(-1d0/q**2))))-1.5d0)<BR>
<BR> vx=(-gam/(6d0*pie))*((-4d0*dexp(-1d0/q**2)/q)
&<BR> +2d0*q**2*(1d0-dexp(-1d0/q**2)) & <BR>
-2d0*(dexp(-1d0/q**2)*(q**2-2d0)/q)-2d0*dsqrt(pie)*derf(1d0/q) &
<BR>
-2d0*q+2d0*q*(q**2-2d0)*(1d0-dexp(-1d0/q**2))+4d0*dsqrt(pie)*derf(1d0/q))
&<BR>
+(2d0*gam/(3d0*pie*q))*(q**2*(((2d0*dsqrt(pie)/q)*derf(1d0/q))-1d0+
&<BR> ((q**2-2d0)*(1d0-dexp(-1d0/q**2))))-1.5d0)<BR>
<BR> !<BR> return<BR>end subroutine slater_bnl</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Is this sufficient, or are there any other routines
I need to change?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Thanks for your help,</FONT></DIV>
<DIV><FONT face=Arial size=2>Helen Eisenberg</FONT></DIV></BODY></HTML>