Author Topic: how to generate alpha and beta spin density cube files  (Read 2911 times)

golden

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how to generate alpha and beta spin density cube files
« on: January 23, 2014, 07:49:46 pm »
Dear All,
    I need to calculate the alpha and beta spin density of a open-shell system. 

By using;
$pointval dens fmt=cub

    in the control file I was able to generate two cube files namely "sd.cub"  and "td.cub" which has the " alpha - beta " , "alpha + beta" spin density.  (I was using ridft -proper to generate this.)

My question is ::  Is there anyway that I could generate alpha & beta spin densities separately ?

Thanks

gd

uwe

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Re: how to generate alpha and beta spin density cube files
« Reply #1 on: January 27, 2014, 03:42:09 pm »
Hello,

there are several ways to do that, but there is no special and simple keyword for it.

1. cub format is ASCII, so you could read both files in and add/subtract the numbers and multiply by 1/2 and -1/2 resp.

or

2. to plot just alpha, copy the file alpha to beta, change in the file beta the header from $scfmo_alpha to $scfmo_beta and copy within the control file the keyword $alpha shells to $beta shells (or change the occupation in beta shells to the same value as alpha shells). Then run ridft -proper to get the alpha density in the file td.cub. Same for beta, just vice versa.

or

3. remove the keyword $uhf, copy $alpha shells to $closed shells (change the occupation from 1 to 2 if you want), copy the file alpha to mos and change the header in mos from $scfmo_alpha to $scfmo. Then ridft -proper will again give the alpha density in the file td.plt.

Uwe