Dear Mark,<br> <br> Thank you for your reply, According to my understanding functional form of dihedral function type 9 is same as dihedral function type 1 i.e k (1 + cos(n (phi)- phi s)) except the difference that function type 9 is used to handle the multiple potential functions to be applied to the single dihedreal, Is my understanding correct ?.<br>
The functional form that I am using Summn over 'n' 0.5*K [ ( Cos n(phi-phi0)] , Here 1<= n <= 3 is different from the k (1 + cos(n (phi)- phi s)). I am suspecting can I use function type 9 for my function.<br>
Can you please clarify my doubt.<br><br>Thank you in advance.<br><div class="gmail_quote">On Mon, Jun 4, 2012 at 12:55 PM, Mark Abraham <span dir="ltr"><<a href="mailto:Mark.Abraham@anu.edu.au" target="_blank">Mark.Abraham@anu.edu.au</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="im">On 4/06/2012 3:46 AM, ramesh cheerla wrote:<br>
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Dear Gromacs experts,<br>
<br>
I am planing to use tabulated potentials for dihedral functional form Summn over 'n' 0.5*K [ ( Cos n(phi-phi0)] , Here 1<= n <= 3 . I have three different K values (i.e K1,K2,K3 ) one for each 'n' value ( Here 'n' is multiplicity).<br>
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You do not need a table for this - type 9 will do the job easily, and for friendly values of phi0, there exists an equivalent form to the above that can be expressed as a Ryckaert-Belleman dihedral. See various places of manual chapters 4 and 5.<div class="im">
<br>
<br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
I have generated table and given the table number in dihedrals directive of the ffbonded.itp file, According to my understanding one has to supply K ( force constant ) value in addition to table number in topology. In my case I have three different "K" values, which "k" value do I have to take, Can I take sum of all the three "k" values or can I take arbitrary value.<br>
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Your table would need to be the weighted sum of the three cosines, so apparently you have not yet generated such a table. But rather than buy trouble, go and do the easier and faster solutions above :-)<span class="HOEnZb"><font color="#888888"><br>
<br>
Mark<br>
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