mirror of
https://github.com/nwchemgit/nwchem.git
synced 2026-07-26 13:15:29 -04:00
132 lines
4 KiB
HTML
132 lines
4 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
|
|
"http://www.w3.org/TR/html4/loose.dtd">
|
|
<HTML>
|
|
<HEAD>
|
|
<TITLE>NWChem Frequently Asked Questions</TITLE>
|
|
<link rel="stylesheet" type="text/css" href="../../shared/nwchem_basic.css">
|
|
</HEAD>
|
|
|
|
<body text="#000000" bgcolor="#FFFFFF" link="blue" alink="blue" vlink="blue">
|
|
<table width="650"><tr><td>
|
|
<br>
|
|
<table>
|
|
<tbody>
|
|
<tr>
|
|
<td align="left" width="325"><img src="../../images/nwchem_logo_dark.gif" border=0 width=200 alt="NWChem - computational chemistry on parallel computers"></td>
|
|
<td align="right" width="325" valign="bottom">
|
|
<a href="../../nwchem_main.html">NWChem Home</a> |
|
|
<a href="../../disclaimer.html">Security & Privacy</a> |
|
|
<a href="http://www.pnl.gov" target="_blank">PNNL</a>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<hr>
|
|
<table width="650">
|
|
<tbody>
|
|
<tr>
|
|
<td width="350" align="left"></td>
|
|
<td width="300" align="right"><a href="dft.html">Next FAQ Catagory</a> | <a href="NWChem_FAQ.html">Return to Main FAQ</a></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<br><br>
|
|
<h1>NWChem FAQ</h1>
|
|
|
|
<p><h2>MP2 Properties</h2>
|
|
|
|
<!--DO NOT REMOVE Begin Question and End Question Comments.-->
|
|
<ul>
|
|
<!--Begin Question-->
|
|
<li><a href="#0">How do I calculate MP2 properties? </a></li>
|
|
<li><a href="#1">My high symmetry MP2 calculation is taking longer that it should. Why is this?</a></li>
|
|
<!--End Question-->
|
|
</ul>
|
|
|
|
<hr>
|
|
<p>
|
|
<a name="0"></a>
|
|
<font color="purple">How do I calculate MP2 properties?
|
|
</font>
|
|
<p>
|
|
The default molecular orbital file
|
|
$file_prefix$.movecs is used unless a VECTORS
|
|
subdirective is provided in the PROPERTY directive. It is therefore
|
|
necessary to include a VECTORS directive if the MO
|
|
vectors to be analyzed are not coming from the default
|
|
file, e.g., if they have been previously redirected, or if
|
|
MP2 natural orbitals (file extension ".mp2nos") are
|
|
being anaylzed. So, to calculate MP2 properties, a PROPERTY
|
|
block directive similar to the one in the following example would
|
|
be appropriate:
|
|
<pre>
|
|
start h2o
|
|
title; Water MP2 properties example
|
|
|
|
geometry
|
|
O 0 0 0
|
|
H 0 1.430 1.107
|
|
H 0 -1.430 1.107
|
|
end
|
|
|
|
basis
|
|
H library sto-3g
|
|
O library sto-3g
|
|
end
|
|
|
|
task mp2
|
|
|
|
property
|
|
octupole
|
|
efield
|
|
vectors h2o.mp2nos
|
|
end
|
|
|
|
task property
|
|
</pre>
|
|
</p>
|
|
|
|
<hr>
|
|
<p>
|
|
<a name="1"></a>
|
|
<font color="purple">My high symmetry MP2 calculation is taking longer that it
|
|
should. Why is this?
|
|
</font>
|
|
<p>
|
|
Currently MP2 can only use Abelian point groups and does not have descent of
|
|
symmetry implemented (meaning that it does not know how to use a proper
|
|
Abelian point group instead of an input non-Abelian group). The user must
|
|
define the proper Abelian point group, orient the molecule into this point
|
|
group, and then run the MP2.
|
|
</p>
|
|
<p>
|
|
<hr>
|
|
<font size="0">
|
|
<center>
|
|
<a href="../../nwchem_main.html">NWChem</a> |
|
|
<a href="../../capabilities/nwchem_capab.html">Capabilities</a> |
|
|
<a href="../../platforms/platforms.html">Platforms</a> |
|
|
<a href="../../download.html">Download</a> |
|
|
<a href="../../doc/user/index.html">User's Manual</a> |
|
|
<a href="../../doc/prog/index.html">Programmer's Manual</a> |
|
|
<a href="../../release-notes/index.html">Release Notes</a> |
|
|
<a href="NWChem_FAQ.html">FAQ</a>
|
|
</center>
|
|
<br>
|
|
<center>
|
|
<a href="../known_bugs.html">Known Bugs</a> |
|
|
<a href="../support.html">Support</a> |
|
|
<a href="../../training/training.html">Tutorial</a> |
|
|
<a href="../../contributors.html">Contributors</a> |
|
|
<a href="../../benchmarks/index.html">Benchmarks</a> |
|
|
<a href="http://www.emsl.pnl.gov/forms/search_nwchem.html">Search</a> |
|
|
<a href="http://www.emsl.pnl.gov/docs/mssg/index.html" target="_blank">Mol Sci. Soft. Group</a> |
|
|
<a href="../../citation.html">Citation</a>
|
|
</center>
|
|
</font>
|
|
<hr>Contact: <a href="mailto:ms3distribution@emsl.pnl.gov">NWChem Support</a><br>
|
|
Updated: February 22, 2005
|
|
</td></tr>
|
|
</table>
|
|
</body>
|
|
</html>
|