[AMBER] QM/MM energy terms with DFTB

From: Markus Kaukonen <markus.kaukonen.iki.fi>
Date: Thu, 16 Dec 2010 17:49:50 +0200

Dear Amber,

This issue has already been dealt with on this list, but I did not
quite get it, so here we go again:

In QM/MM calculation with DFTB as QM engine one gets output like (with Amber10)

      1 -2.1816E+04 1.7957E+01 1.4342E+02 C36 12502

 BOND = 2156.1278 ANGLE = 6029.2390 DIHED = 9228.7109
 VDWAALS = -7560.4126 EEL = -52399.6187 EGB = -5475.9033
 1-4 VDW = 2123.9140 1-4 EEL = 37427.0797 RESTRAINT = 0.0000
 DFTBESCF= -13345.6223

Question: What is included in the term 'DFTBESCF'
Is it only the QM energy of the QM region (terminated with H atoms)
and electrostatic interaction of QM nuclei and electron cloud with
unscaled point charges of the MM region?

Vdw interaction between QM and MM region is in included into 'VDWAALS'
and '1-4 VDW' ?
Possible bond, angle and dihedral terms between QM and MM regions are
included into the classical terms (BOND, ANGLE, DIHED)?
Solvation energy of QM region is in included into EGB ?

Did I get it right?

terveisin, Markus

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Received on Thu Dec 16 2010 - 08:00:02 PST
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