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issp-center-dev / mVMC

A numerical solver package for a wide range of quantum lattice models based on many-variable Variational Monte Carlo method
http://www.pasums.issp.u-tokyo.ac.jp/mvmc/en/
GNU General Public License v3.0
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No spin projection? #13

Closed nikita-astronaut closed 4 years ago

nikita-astronaut commented 4 years ago

Dear mVMC team,

I would like to simulate the Hamiltonian with only S_z conserved, but SU(2)--nonsymmetric (only U(1)--symmetric). This means, that the exchange term is multiplied by some lambda != 1.

Is it possible to switch off completely the S_tot projector in the expert mode? By reading the docs I could not understand if it is really possible.

Setting NSPGaussLeg 0 leads to the errors of the kind warning: VMCMainCal rank:0 sample:999 e=-nan StcOpt: r[0]=-nan Error: StcOpt info=1 step=0

Thanks a lot!

tmisawa commented 4 years ago

Dear Nikita Astrakhantsev,

By setting 

NSPGaussLeg 1

you can switch off the spin projection.

Best, Takahiro Misawa

nikita-astronaut commented 4 years ago

Dear Takahiro

thank you so much! This team is always so helpful.