CCL: Easy convergence of Diffuse functions

[errol lewars <elewars**trentu.ca>]

 Sent to CCL by: errol lewars [elewars%trentu.ca]
 2008 Aug 31
 Convergence problems with diffuse functions is a well-known phenomenon.
You could try getting a wavefunction with, say, the 6-31G*  basis then
 using that wavefunction as an initial guess for a 6-31+G* job. The
 keyword for  taking the previous wavefunction as your guess depends on
 your program.
 E. Lewars
 ===
 Mr Shabbir shabbir!=!nenu.edu.cn wrote:
>  Sent to CCL by: "Mr  Shabbir" [shabbir]^[nenu.edu.cn]
>  Dear all
>  I want to share some thing about optimization. I optimized several systems with
>  6-31G* basis set but when I use diffuse function (+) the same previously
>  optimized system at (6-31G*) fails to converge by using diffuse function. How to
>  treat the diffuse function especially in optimization? Is there any special
>  keyword or way that can make the convergence easy with diffuse functions?
>  Regards
>  Mr.Shabbir
>  shabbir::nenu.edu.cn>
>  
>