AMBER: resp error message

From: Andre Farias de Moura <>
Date: Wed, 29 Sep 2004 16:25:07 +0000 (GMT)


I'm using resp to generate the atomic charges of an
organic molecule but I'm getting the following error

  110 0.4900804E+02 0.5598209E+01 0.1869775E+02
  111 0.4598422E+02 0.6976337E+01 0.1952414E+02
  112 0.4637003E+02 0.3577767E+01 0.1952502E+02
 Initial ssvpot = 0.736

 Number of unique UNfrozen centers= 106

 Non-linear optimization requested.
 chgopt: LU decomp gave almost-singular U

at the first stage of the calculation my input file was:

  ioutopt=1, iqopt=1, nmol=1, ihfree=1, irstrnt=1, qwt= 0.0005
   0 112
   6 0
   1 0
   1 0
   1 0
   6 0

all the atoms had ivary=0 except for the oxygen atoms, which
were constrained to be equal.

I managed to do the resp fitting of a smaller homologue with
the same input options.

I would appreciate any comments on the subject,

thanks in advance,



    Dr. Andre' Farias de Moura


  Laboratorio de Quimica Teorica
Universidade Federal de Sao Carlos
     Sao Carlos - SP - Brasil


        Endereco Atual

    Grupo de Quimica Quantica
Instituto de Quimica de Sao Carlos
    Universidade de Sao Paulo
    Sao Carlos - SP - Brasil
    Telefone: 55-16-3373-8055


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Received on Wed Sep 29 2004 - 20:53:00 PDT
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