Dear Mr. Ding-Wang Yuan,

By calculating the (frequency-dependent) first hyperpolarizability
tensor beta in small
electric fields:

EFIELD 0 0 0.001

and separately

EFIELD 0 0 -0.001

and the same for fields in the x and y directions,
you can numerically differentiate all beta-tensor components to
obtain the corresponding values for the gamma-tensor components.

As a test, you could start with the He atom, in which case beta = 0 and
there is
only one independent component of gamma.

Diffuse functions and the DEPENDENCY keyword are probably needed for
reliable results.

Best regards,
Stan van Gisbergen

On Jun 29, 2004, at 4:02 PM, DingWang Yuan wrote:

> Dear Friends,
> I want to calculate the second hyperpolarizabilities of some small
> molecules. The user's guide tell us "some can be obtained by
> calculating the first hyperpolarizability in a finite field".
> Could you tell me how can I obtain them in details or offer me some
> further information about that?
>
> Thanks a lot in advance .
>
>
> Mr. Ding-Wang Yuan
> Key Laboratory of Materials Physics,
> Institute of Solid State Physics,
> Academia Sinica, P.O.Box 1129,
> Hefei 230031,P.R.~China
> Tel :0086-551-5591464(Office)
> 0086-551-5592837(Home)
> Fax :0086-551-5591434
>
>
Dr. S.J.A. van Gisbergen      
Scientific Computing & Modelling NV
Theoretical Chemistry, Vrije Universiteit
De Boelelaan 1083
1081 HV Amsterdam
The Netherlands                              
T: +31-20-4447626    
F: +31-20-4447629        
vangisbergen_at_scm.com  
http://www.scm.com
Received on 2004-06-23 08:50:32