<html>
<head>
<style><!--
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
font-size: 10pt;
font-family:Tahoma
}
--></style>
</head>
<body class='hmmessage'>
<style><!--
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
font-size: 10pt;
font-family:Tahoma
}
--></style>
Thank you Mark for your response,<br><br>In carrying out the test you recommended I realised that I had set the integrator to sd, in such a case the tcoupl parameter is ignored. This explains my well behave temperature in the absence of setting a tcoupl option. When I wrote the input file originally (months ago) I must have known what I was doing but then we live, we learn, we forget.<br><br>Regards<br><br>Charlie<br> </body>
</html>