Can a DynMat calculation for an isolated molecule be done?
Posted: Sat Feb 06, 2010 8:48 pm
Dear guys,
I need the zero point energy (ZPE) of a gas phase molecule like ethane. My quesitions are:
1. Can we get the vibration frequencies of an isolated molecule in a big box by a Dynamical Matrix calculation?
2. If we can, how do I prepare the DISPLACECAR file? Take ethane (8 atoms) as an example, if I want the displacement to be 0.001, should I just write 8 lines of 0.001, 0.001, 0.001 in the DISPLACECAR file?
3. How do I specify NSW? Is it equal to 3*8+1=25? If I specify NSW to be more than 25, for instance, 30, would I still get the right results?
Thanks a lot.
I need the zero point energy (ZPE) of a gas phase molecule like ethane. My quesitions are:
1. Can we get the vibration frequencies of an isolated molecule in a big box by a Dynamical Matrix calculation?
2. If we can, how do I prepare the DISPLACECAR file? Take ethane (8 atoms) as an example, if I want the displacement to be 0.001, should I just write 8 lines of 0.001, 0.001, 0.001 in the DISPLACECAR file?
3. How do I specify NSW? Is it equal to 3*8+1=25? If I specify NSW to be more than 25, for instance, 30, would I still get the right results?
Thanks a lot.