scaling of casino
Posted: Fri Nov 28, 2014 1:59 pm
I am wondering how runtime is influenced by a.) the blip multiplicity and b.) the parameters in the Jastrow:
I expect that that the answer to a.) is: runtime is independent of blip multiplicity since each point in space is only contained in 3 B-splines (per dimension) independently of the multiplity. This is also what I observe in my calculations - I just want to make sure this is correct.
Concerning b.): I suppose that the Jastrows have to be calculated each time an electron configuration is moved in DMC. Am I correct in assuming that the calculation time spent to recalculate the Jastrow scales linearly with the number of Parameters and to the third power of the cutoff radius? Or is this nonsense? If it is correct, how expensive are the Jastrows? Might it make sense to use shorter cutoffs, if a larger cutoff doesn't influence the energy significantly?
P.S. sorry for asking so many questions, but I need to shed some light into this still rather gray (not entirely black) box called Casino.
I expect that that the answer to a.) is: runtime is independent of blip multiplicity since each point in space is only contained in 3 B-splines (per dimension) independently of the multiplity. This is also what I observe in my calculations - I just want to make sure this is correct.
Concerning b.): I suppose that the Jastrows have to be calculated each time an electron configuration is moved in DMC. Am I correct in assuming that the calculation time spent to recalculate the Jastrow scales linearly with the number of Parameters and to the third power of the cutoff radius? Or is this nonsense? If it is correct, how expensive are the Jastrows? Might it make sense to use shorter cutoffs, if a larger cutoff doesn't influence the energy significantly?
P.S. sorry for asking so many questions, but I need to shed some light into this still rather gray (not entirely black) box called Casino.