Question regarding electronic ground state

[chuckschuldiner]

hi can anyone please help me

I came across this statement "Since we only consider the electronic ground state of the system, there can be no net force or torque acting upon the subsystem of classically behaving nuclei". Can anyone explain what this means?

 

[scarecrow]

The ground state of an atom refers to its lowest energy state. In other words, it is not interacting/reacting with other atoms. The net force or torque that is mentioned is referring to such interactions of the electrons.

 

[Gokul43201]

hi can anyone please help me

I came across this statement "Since we only consider the electronic ground state of the system, there can be no net force or torque acting upon the subsystem of classically behaving nuclei". Can anyone explain what this means?

Please tell us where you read this and in what chapter and what context.

 

[chuckschuldiner]

scarecrow thanks but can u explain in some more detail?

gokul this is from a paper " quantum mechanical stress and a generalized virial theorem for clusters and solids", phys rev b vol 37 (pp 8167).

the paper deals with providing a quantum mechanical framework for stress and force but since i have a mech engg background i am having some difficulties. thanks for helping out

 

[quetzalcoatl9]

hi can anyone please help me

I came across this statement "Since we only consider the electronic ground state of the system, there can be no net force or torque acting upon the subsystem of classically behaving nuclei". Can anyone explain what this means?

this is the basis of Carr-Parinello quantum dynamics - an extended langrangian is used to impose constraints that force the electrons into the ground state. it's gets results similar to born-oppenheimer MD at a fraction of the computational cost