[CPMD-list] difference between C_MT_BLYP_2 and C_MT_BLYP_1

[Axel Kohlmeyer]

On Fri, 28 Dec 2007, liu liuxiandong wrote:

XL> Dear CPMDers,
XL> 
XL>   What is the difference between C_MT_BLYP_2 and C_MT_BLYP_1 included
XL> in the pplib folder ? They seem very similar to each other. I want to

one is "hard" and the other "soft". please see the differences 
in the pseudization cutoffs. in general, "harder" pseudopotentials
are more transferable, but require a larger plane wave cutoff.

XL> simulate the geometries of some charged organic anions with MT_BLYP
XL> types. Thanks for any suggestions.

this looks as if you need the "hard" version (blyp_1, IIRC).
if you have "harder" elements (e.g. oxygen) in your system,
they determine the planewave cutoff anyways. so there is no
advantage from using the "soft" version.

cheers,
  axel.

XL> 
XL> 
XL> BEST,
XL> 
XL> Xiandong Liu
XL> _______________________________________________
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XL> CPMD-list at cpmd.org
XL> http://cpmd.org/mailman/listinfo/cpmd-list
XL> 

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Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
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