<div dir="ltr"><div>The difference in exponents between Molpro library and EMSL is surprising. It is caused by the fact that 6-31G basis specification involves additional scaling factor for inner and outer valence contractions (the first and second contractions). This is explained in the "Molecular Electronic Structure Theory" book by Helgaker.<br>
<br>For Hydrogen the inner valence and outer valence have scaling factors sqr(1.2) and sqr(1.15). The Molpro library entry does not include this scaling factor but the program adds it later, whereas EMSL includes it right away<br>
<br></div><div>Sham.<br></div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Jun 17, 2014 at 7:05 PM, Jayashree <span dir="ltr"><<a href="mailto:yfpjaya@gmail.com" target="_blank">yfpjaya@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_default" style="font-family:times new roman,serif;font-size:small">Indeed, I think I have an issue with the factors. I have been using the EMSL basis library, which has different exponents from those in the MOLPRO basis library. Thanks for pointing this out! If I understand correctly, the library has the following columns for a given basis set:<br>
<br><table><caption>Basis H s <a href="http://www.molpro.net/info/basis.php?version=current&describe=1&element=H&basis=631G" target="_blank">631G</a></caption>
<thead><tr><th>Primitives</th><th colspan="2" align="left">Contractions...</th></tr></thead>
<tbody>
<tr char="." align="char"><td>13.007730</td><td>0.033495</td><td>0.000000</td></tr>
<tr char="." align="char"><td>1.962079</td><td>0.234727</td><td>0.000000</td></tr>
<tr char="." align="char"><td>0.444529</td><td>0.813751</td><td>0.000000</td></tr>
<tr char="." align="char"><td>0.121949</td><td>0.000000</td><td>1.000000</td></tr></tbody></table><br></div><div class="gmail_default" style="font-family:times new roman,serif;font-size:small">Is the 1st column exponent, 2nd the coefficient? What is the third column for?<br>
</div><div class="gmail_default" style="font-family:times new roman,serif;font-size:small"><br></div><div class="gmail_default" style="font-family:times new roman,serif;font-size:small">From your mail, I gather that MOLPRO library basis functions are NOT normalised-- is this correct? I believe the analogous ones in EMSL are. For example the same basis above in EMSL is<br>
<pre style="font-family:Courier,fixed;margin-left:10px">BASIS "ao basis" PRINT
#BASIS SET: (4s) -> [2s]
H S
18.7311370 0.03349460
2.8253937 0.23472695
0.6401217 0.81375733
H S
0.1612778 1.0000000
END
</pre><span class="HOEnZb"><font color="#888888"><br></font></span></div><span class="HOEnZb"><font color="#888888"><div class="gmail_default" style="font-family:times new roman,serif;font-size:small">Jayashree<br>
</div></font></span><div><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On 16 June 2014 02:00, Gerald Knizia <span dir="ltr"><<a href="mailto:knizia@theochem.uni-stuttgart.de" target="_blank">knizia@theochem.uni-stuttgart.de</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>On Wed, 2014-06-11 at 07:17 -0400, Jayashree wrote:<br>
<br>
> I generated and saved a 3D grid in a molpro output file. The x,y,z<br>
</div>> coordinates and weights (w_k) are printed for each atom. [...]<br>
<div>> If I then sum the atomic contributions, I should get the total number<br>
> of electrons. My question is:<br>
> Is there a missing factor involved in this formula?<br>
> I tried a simple test of evaluating the atomic contribution to the<br>
> electron ground state density where F stands for<br>
> F(x,y,z) = sum(AO1,AO2) AO1(x,y,z)* AO2(x,y,z) Denmat(AO1,AO2)<br>
> , and did not obtain the correct number of electrons.<br>
<br>
<br>
</div>I think this should work. The weights themselves represent the volume of<br>
their respective integration points, and if you use them to sum the<br>
number of electrons like this, you should get the total number of<br>
electrons.<br>
<br>
Are you sure that you have all normalization factors correctly applied<br>
in the AOs themselves? A common problem when evaluating basis functions<br>
is missing the factors between raw primitive Gaussians and normalized<br>
primitive Gaussians (i.e., the factor converting between "library<br>
format" of the contraction coefficients (which refer to primitive<br>
functions normalized such that Int[r in R^3] mu^2(r) d^3r = 1) to what<br>
you actually use in the code).<br>
<br>
Beware also of the order of basis functions. Molpro's order of solid<br>
harmonic functions is particularly creative.<br>
<span><font color="#888888">--<br>
Gerald Knizia<br>
<br>
<br>
</font></span></blockquote></div><br></div></div></div></div>
<br>_______________________________________________<br>
Molpro-user mailing list<br>
<a href="mailto:Molpro-user@molpro.net">Molpro-user@molpro.net</a><br>
<a href="http://www.molpro.net/mailman/listinfo/molpro-user" target="_blank">http://www.molpro.net/mailman/listinfo/molpro-user</a><br></blockquote></div><br></div>