Subject: ecp format

From: [email-masked] (Jennie Weston)
Date: Fri, 28 Feb 1997 13:17:01 +0100 (CET)

Hello Everybody,

Maybe somebody out there can help me... I happen to need an effective
core potential for potassium - in Gaussian 94 format. SO i looked in 
the Stuttgart ecp library. Here's what i found:

K ECP ECP10MWB: 10 4 0 20
Q=9., MEFIT, WB, A: Bergner, Arbeitsbericht 1990.
1 2 1.000000 0.000000
1 2 6.843807 92.252639
1 2 4.217857 23.498035
1 2 6.497537 -7.315420
1 2 6.123613 -3.858320
K s ECP10MWB : 7 1 1.3
(7s6p)/[5s4p]-Basissatz fuer PP von A. Bergner, Arbeitsbericht 1990.
 8.223362  3.797211  1.331607 0.666282
 0.272807  0.037092  0.016543
 0.104145 -0.439158  0.052191
K p ECP10MWB : 6 1 1.3
(7s6p)/[5s4p]-Basissatz fuer PP von A. Bergner, Arbeitsbericht 1990.
21.605670 1.100212 0.504345 0.317869
 0.148150 0.022139
-0.011737 -0.407675 -0.333292
***********************************

As i am a complete newbie in the field of ecp calculations, i could really
use some help translating these numbers into an input file for gaussian94. 
I need to be able to read the ecp and accompanying basis set in with the
GEN keyword.  Could some guru out there take 10 min of time and help?
This would REALLY be appreciated.  
Reply to [email-masked] 
to save ccl bandwidth for this very specific problem. If anybody else is
interested in the results, give me an email jingle.

Thanks a bunch,

Jennie Weston

Here's what i have so far:

-----input specification, then start basis set

K 0
S       3       1.00
0.8223362D+01    0.104145D+00
0.3797211D+01   -0.439158D+00
0.1331607D+01    0.52191D-01
S       1       1.00
0.666282D+00     0.1000000D+01
S       1       1.00
0.272807D+00     0.1000000D+01 
S       1       1.00
0.370920D-01     0.1000000D+01 
S       1       1.00
0.16543D-01      0.1000000D+01
P       3       1.00
0.21605670D+02  -0.117370D-01
0.1100212D+01   -0.407675D+00
0.504345D+00    -0.333292D+00
P       1       1.00
0.317869D+00     0.1000000D+01 
P       1       1.00
0.148150D+00     0.1000000D+01
P       1       1.00
0.221390D-01     0.1000000D+01
****

is this right so far?.....and then i get stuck with the ecp block.

Here is the (very minimal) explanations provided by the Stuttgart 
library in conjunction with these numbers:

Library keywords are of the form ECPnXY; n is the number of core electrons
which are replaced by the pseudopotential, X denotes the reference system
used for generating the pseudopot (X=S: single-valence-electron ion; X=M:
neutral atom), and Y stands for the theoretical level of the reference 
data (Y=HF: Hartree-Fock; Y=WB: quasi-relativistic; Y=DF: relativistic).
For one- or two-valence electron atoms SDF is a good choice, while otherwise
MWB (or MDF) is recommended.  The same keyword applies to the set of pseudopot
parameters and the corresponding optimized valence basis sets.

For each pseudopot, the keyword is immediately followed by 4 parameters:
the number of core electrons, the number of l-projectors (lmax), a zero
for scalar-relativistic ECP's, and the total number of parameters listed below
the commentary line. The latter parameters provide information on V(lmax) 
first, and then for the semi-local V(l) in the order l=0,1,2,.., lmax-1.
For each l, the number of terms of the form A(i)*r**(n(i)-2)*exp(a(i)*r**2)
is given first, and then the parameters specifying the individual terms
in the sequence n(1),a(a),A(1);n(2)a(2),A(2);....

For each valence basis set of a specified symmetry (s, p, d, ...), the
number of exponents is specified first, then the number of recommended
contractions and the contraction patterns (n.m defines the range of 
primitives to be contracted). On the following lines, the exponents of
the primitives are given first, and afterwards the sets of contraction
coefficients.

---end of library explanations----