<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>Dear Magnus,</p>
<p>but do you have any reasons to expect that these methods must
yield similar results? They are different and both are not so
precise for the systems with complicated electronic effects.</p>
<p>Yours,</p>
<p>Anton<br>
</p>
<div class="moz-cite-prefix">01.09.2022 12:48, Magnus Rahm пише:<br>
</div>
<blockquote type="cite"
cite="mid:2b7a001c-6e70-4e27-bb1d-cd6c1f4765f9n@googlegroups.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
Dear all,<br>
<br>
I want to use CP2K (version 8.2, trying to get a more recent
version compiled) together with xTB for a crystal containing Li
and O. I get strange results already for a simple LiO2 crystal:<br>
<br>
* There is a very large discrepancy compared to DFTB+ (version
22.1).<br>
* Mulliken charges tend to be large, meaning that
CHECK_ATOMIC_CHARGES stops the SCF. If I turn it off, the system
tends to converge systematically to values just outside the
"chemical range". Mulliken charges obtained by DFTB+ are
significantly smaller (and within "chemical range").<br>
* The energy-volume curve looks strange and very different from
DFTB+.<br>
<br>
I have tried converging with respect to system size and the EWALD
/ ALPHA and GMAX parameters, but they have only a marginal impact.
I have tried similar calculations for a number of periodic
systems. Sometimes I get agreement, sometimes not. I also tried
calculations for CO and NO molecules which agree perfectly between
CP2K and DFTB+, whereas an artificial LiF molecule does not.<br>
<br>
A perhaps related issue was reported in
<a class="moz-txt-link-freetext" href="https://groups.google.com/g/cp2k/c/oFwgGcQuySs">https://groups.google.com/g/cp2k/c/oFwgGcQuySs</a> but the solutions
suggested there did not solve my problem.<br>
<br>
I attach input scripts for CP2K and DFTB+, as well as a figure
showing the E-V curve for LiO2 obtained with CP2K and DFTB+. I'm
new to CP2K, DFTB+ and xTB so I suspect I have made some simple
mistake, and any advice is appreciated.<br>
<br>
Kind regards,<br>
Magnus Rahm<br>
<br>
<br>
<br>
<br>
<br>
-- <br>
You received this message because you are subscribed to the Google
Groups "cp2k" group.<br>
To unsubscribe from this group and stop receiving emails from it,
send an email to <a
href="mailto:cp2k+unsubscribe@googlegroups.com"
moz-do-not-send="true" class="moz-txt-link-freetext">cp2k+unsubscribe@googlegroups.com</a>.<br>
To view this discussion on the web visit <a
href="https://groups.google.com/d/msgid/cp2k/2b7a001c-6e70-4e27-bb1d-cd6c1f4765f9n%40googlegroups.com?utm_medium=email&utm_source=footer"
moz-do-not-send="true">https://groups.google.com/d/msgid/cp2k/2b7a001c-6e70-4e27-bb1d-cd6c1f4765f9n%40googlegroups.com</a>.<br>
</blockquote>
</body>
</html>
<p></p>
-- <br />
You received this message because you are subscribed to the Google Groups "cp2k" group.<br />
To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>.<br />
To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/4c881173-e0e6-ff04-cd7b-3296d758f709%40gmail.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/4c881173-e0e6-ff04-cd7b-3296d758f709%40gmail.com</a>.<br />