Subject: Problem with an MP2 calculation using G94

From: Bart Rousseau <[email-masked]>
Date: Wed, 14 May 1997 16:37:31 +0200

Hello,

We did an MP2 calculation (see attached input file) and
tried to calculate Trace(PS) where P is the MP2 density
matrix and S the overlap matrix. This should of course
be equal to N, the total number of electrons.
For our system which has 20 electrons we get a
value of 19.383 instead of 20. Does anybody know what
went wrong? Or have we missed something?

Thanks in advance,
Bart.

ps We use G94 Rev D.4 on a Digital AlphaStation running 
Digital UNIX 4.0B.
-- 
-----------------------------------------------
|Bart Rousseau, Ph.D. student                 |
|University of Antwerp - Dep. of Chemistry    |
|Structural Chemistry  - Quantum Chemistry    |
|Universiteitsplein 1  - 2610 Antwerpen       |
|Belgium               - [email-masked]    |
|http://sch-www.uia.ac.be/struct/quantum/     |
[email-masked]       - [email-masked]|
|Tel.: + 32 3 8202366  - Fax.: + 32 3 8202356 |
-----------------------------------------------
%Mem=128MB
%Chk=abcd.chk

#P RMP2(Full,FullDirect)/Gen Density=current Units=au Pop=Full Test

Test 3-21G

0 1
H   0.0042351 -1.4679457 1.2424573   
N  -0.0563628  0.3422276 0.7070346   
Li -1.6080807  1.2276114 1.3197142   
F   1.5279278  1.2776066 1.1338566   

H 0
S    2 1.00
 0.5447178000D+01  0.1562850000D+00
 0.8245472400D+00  0.9046910000D+00
S    1 1.00
 0.1831915800D+00  0.1000000000D+01
****
N 0
S    3 1.00
 0.2427660000D+03  0.5986570000D-01
 0.3648510000D+02  0.3529550000D+00
 0.7814490000D+01  0.7065130000D+00
S    2 1.00
 0.5425220000D+01 -0.4133010000D+00
 0.1149150000D+01  0.1224420000D+01
S    1 1.00
 0.2832050000D+00  0.1000000000D+01
P    2 1.00
 0.5425220000D+01  0.2379720000D+00
 0.1149150000D+01  0.8589530000D+00
P    1 1.00
 0.2832050000D+00  0.1000000000D+01
****
Li 0
S    3 1.00
 0.3683820000D+02  0.6966860000D-01
 0.5481720000D+01  0.3813460000D+00
 0.1113270000D+01  0.6817020000D+00
S    2 1.00
 0.5402050000D+00 -0.2631270000D+00
 0.1022550000D+00  0.1143390000D+01
S    1 1.00
 0.2856450000D-01  0.1000000000D+01
P    2 1.00
 0.5402050000D+00  0.1615460000D+00
 0.1022550000D+00  0.9156630000D+00
P    1 1.00
 0.2856450000D-01  0.1000000000D+01
****
F 0
S    3 1.00
 0.4138010000D+03  0.5854830000D-01
 0.6224460000D+02  0.3493080000D+00
 0.1343400000D+02  0.7096320000D+00
S    2 1.00
 0.9777590000D+01 -0.4073270000D+00
 0.2086170000D+01  0.1223140000D+01
S    1 1.00
 0.4823830000D+00  0.1000000000D+01
P    2 1.00
 0.9777590000D+01  0.2466800000D+00
 0.2086170000D+01  0.8523210000D+00
P    1 1.00
 0.4823830000D+00  0.1000000000D+01
****