# Combiner built-in function issue for virtual bond index from MPO with quantum number conservation

**URL:** <https://itensor.discourse.group/t/combiner-built-in-function-issue-for-virtual-bond-index-from-mpo-with-quantum-number-conservation/1605>\
**Category:** ITensor Julia Questions\
**Tags:** mps, mpo\
**Created:** [April 2, 2024, 2:12am UTC](https://itensor.discourse.group/t/combiner-built-in-function-issue-for-virtual-bond-index-from-mpo-with-quantum-number-conservation/1605 "2024-04-02T02:12:28Z")\
**Posts on this page:** 1\
**Showing post:** 8

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**Author:** ![mtfishman](https://yyz2.discourse-cdn.com/free1/user_avatar/itensor.discourse.group/mtfishman/32/11_2.png) [@mtfishman](https://itensor.discourse.group/u/mtfishman)\
**Post date:** [April 2, 2024, 11:31am UTC](https://itensor.discourse.group/t/combiner-built-in-function-issue-for-virtual-bond-index-from-mpo-with-quantum-number-conservation/1605/8 "2024-04-02T11:31:16Z")

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Please format your code, see the post [Please Read: Make It Easier to Help You](https://itensor.discourse.group/t/please-read-make-it-easier-to-help-you/7).

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