Convert and IQMPS to MPS

Question

Hi, is there any existing function in ITensor 1 which can convert IQMPS to MPs? Thank you.

Answer 1

Hi, good question. There is not, so I just added a new function that does this.

If you pull the latest code from GitHub, and do "git checkout version1" which will put you on the version1 development branch, then there is a new function called "toMPS" you can use like this:

IQMPS psi(sites);
... //code that changes psi...

auto psi_mps = toMPS(psi);

Let me know if you encounter any issues with it or have any more questions.

Miles

Comments

Hi Miles,

Would it be possible to add this to the latest version of ITensor? Thanks!

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Hmm you're right: somehow I never added this. Just added it. Please let me know if you encounter any problems with it!

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Hi Miles,

I am just wondering is there a similar function "toMPO" that convert IQMPO to MPO? I have checked that there is actually a "toMPO" function but it is not used in this way. How could I modify that function to convert my IQMPO to MPO?

Best,
Yixuan

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Hi Yixuan,
Sorry for the slow reply! Yes we needed to have this function so I just added it to the latest version of ITensor on github. So please do a "git pull" and recompile and this function should be available. (Just do auto m = toMPO(M); where M is an IQMPO and m will be an MPO.)

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Hi Miles,

Thanks. That will be really helpful.

Best,
Yixuan