This repository contains the interaction files used in
"Nucleus-Dependent Valence-Space Approach to Nuclear Structure" [1].


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======================== File Naming ==========================
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The interaction files are named as
{valence space}_{reference}_{solution method}_hw{frequency}_e{emax}_E{E3max}_A{mass}_{starting interaction}.int

For example,

fp-shell_Ca48_magnus_hw24_e12_E14_A48_srg0800.int

* This is an interaction for the fp-shell valence space
* A Ca48 reference is used for normal ordering.
* The IM-SRG decoupling is performed with the magnus formulation.
* The original single-particle basis is a harmonic oscillator with frequency 24 MeV, in emax=12 i.e. 13 major oscillator shells.
* There is also a cut on three-body matrix elements such that e1+e2+e3 <= E3max, which is 14 in this case.
* The mass A=48 was used in constructing the relative kinetic energy operator.
* The input chiral interaction was free-space SRG evolved to alpha_SRG=0.0800 ~ 1.88 fm^-1.

If you're unsure what these techincal details mean, please consult reference [1], and references therein.

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======================== File Format ==========================
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The files are in the format used by NuShellX@MSU [2].
The *.int files contain the interaction.
All lines beginning with ! are comment lines.
The first non-comment line is
{ignored integer} {spe for orbit 1} {spe for orbit 2} ... {spe for orbit N} {A_core} {Z_core} {A dependent scaling exponent}

where N is the number of single-particle orbits.
All lines thereafter are of the form

a   b   c   d    J   T'     <abJT' | V | c d JT'>

where a,b,c,d are integer indices labeling the valence orbits, J is the total angular momentum,
and T' is an isospin-like parameter used by NuShellX, and V is the two-body interaction.



Note that the proton-neutron two-body matrix elements (TBME) are un-normalized,
while the proton-proton and neutron-neutron TBME are normalized.
To obtain the normalized TBME, take

<aaJ| V |ccJ>_npn    =           <aaJ| V |ccJ>_upn
<abJ| V |ccJ>_npn    = 1/sqrt(2) <abJ| V |ccJ>_upn
<aaJ| V |cdJ>_npn    = 1/sqrt(2) <aaJ| V |cdJ>_upn
<abJ| V |cdJ>_npn    = 1/2       <abJ| V |cdJ>_upn




The *.sp files are used by NuShellX to define the single-particle orbits.



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===================== References ==============================
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[1] S.R. Stroberg, A. Calci, H. Hergert, J.D. Holt, S.K. Bogner, R. Roth, and A. Schwenk,  PRL 118, 302502 (2017)
  arxiv 1607.03229
[2] B. A. Brown and W. D. M. Rae, Nucl. Data Sheets 120, 115 (2014).