VMD-L Mailing List

From: Marzieh Alishahi (alishahi.mar_at_gmail.com)
Date: Mon Dec 24 2012 - 09:13:08 CST

Dear VMD users

I know it might be a simple question, but it would be a great aide if
anyone helps me. I want to write DAT file base my VEL.DCD file. Primarily I
want to compute the mean velocity of water and ion molecules at each time.
But when I want to select both water and ion in an atomselection command no
atom were selected, I used this comment;

> set sel [atomselect top "water and ion" frame 0]

atomselect8

> $sel num

0

> set sel [atomselect top "water" frame 0]

atomselect7

> $sel num

272049

> sel [atomselect top "ion" frame 0]

atomselect9

> $sel num

3524

I can select water and ion in two different selection group, but I want to
know if there is any way to have them both in one selection group?

Any helps is highly appreciated

Best

Marzieh Alishahi