Dear DISPER users,

In response to a recent posting by Dave Price, I can provide some additional
information about the output of the DISPER utility program.

The definitions of the relevant quantities in the output of the disper
program are given in the paper

V.P. Osinga et al. J. Chem. Phys. 106, p.5091 (1997)

in particular in Eq. (8). The C_n^(LA, KA, LB, KB, L) coefficients in this
equation are the "Y" coefficients which are printed. They are scalars.

Eq. (14) provides the definition of the "P" coefficients. These "P"
coefficients do not contain additional information
w.r.t. the "Y" coefficients, but are printed to facilitate comparison to
some earlier work in the literature.

An earlier review paper on which the ADF implementation is based is:

A. van der Avoird et al. Top. Curr. Chem. 93, p.1 (1980)

The Utilities document for the next version will be adapted to contain the
information given here.

Please do not hesitate to contact us if further important information is
not available from the provided documentation.

Best regards,
Stan van Gisbergen,
SCM

Dave Price's original mail:
===========================

Fellow ADF users,
        Please forgive my ignorance (which I know is usually unforgivable)
but I have an output from a Response calc-

 DISPER 2000.02 RunTime: Apr04-2001 14:14:13
********** C-COEFFICIENTS **********
   n LA KA LB KB L coefficient(Y) coefficient(P)
   6 0 0 0 0 0 28.29432373 28.29432373
   6 2 0 0 0 2 7.487547697 3.348533127
   8 0 0 0 0 0 416.1888455 416.1888455
   8 0 0 2 0 2 0.4323024202E-05 0.1933315197E-05
   8 2 0 0 0 2 402.3556946 179.9389368
   8 2 0 2 0 4 0.4238960180E-05
   8 4 0 0 0 4 -36.67895539 -12.22631846
   8 4 0 2 0 6 -0.2000286301E-05

*******************************************************************************

and

 DISPER 2000.02 RunTime: Apr04-2001 14:16:55
********** C-COEFFICIENTS **********
   n LA KA LB KB L coefficient(Y) coefficient(P)
   6 0 0 0 0 0 10.20531904 10.20531904
   8 0 0 0 0 0 137.7385558 137.7385558
   8 0 0 2 0 2 0.1343466074E-05 0.6008162936E-06

*******************************************************************************

Can someone tell me what the difference between Y and P is?
What are the UNITS?
In the case of the diatomic molecule and atom (case 1) how does one
deconvolute these numbers into a simple C6 and C8 centred on the two
atoms
(in the first approximation).
                Dave
Received on 2001-04-11 15:12:02