[Pw_forum] H-bonding in DFT

[Giuseppe Mattioli]

Dear user
Please remember always to sign your post to this forum with name and  
scientific affiliation.

Your question is very general and very difficult, so that a general  
answer is impossible, and a detailed answer depends strongly on your  
system features and on your purposes.

I can therefore only suggest you that unless you are interested in  
very fine details a standard GGA functional should behave decently in  
describing H-bonds, provided that you combine the electrostatic  
interactions inscribed in the GGA description with one of the  
(semiempirical or ab initio) models that add long-range dispersion  
forces.
HTH
Giuseppe

Quoting ZARA NBSH <z.nrbsh at gmail.com>:

> Dear all
>
> ​I would like to study the interaction between two organic molecules
> (contains C, H and O atoms).
> It seems that hydrogen-bonding between H and O atoms of different molecules
> play an important role.
>
> My question is that what is the best method to study this system?
> Could usual DFT (GGA for example blyp PP) have a correct prediction of this
> system?
>
> I really appreciate your help in advance.
>
> WBR
> -NN


-- 
********************************************************
- Article premier - Les hommes naissent et demeurent
libres et égaux en droits. Les distinctions sociales
ne peuvent être fondées que sur l'utilité commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et
imprescriptibles de l'homme. Ces droits sont la liberté,
la propriété, la sûreté et la résistance à l'oppression.
********************************************************

    Giuseppe Mattioli
    CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
    v. Salaria Km 29,300 - C.P. 10
    I 00015 - Monterotondo Stazione (RM)
    Tel + 39 06 90672836 - Fax +39 06 90672316
    E-mail: <giuseppe.mattioli at ism.cnr.it>
    http://www.ism.cnr.it/en/staff/giuseppe-mattioli/
    ResearcherID: F-6308-2012