Overview

Purpose

StdFace is an input file generator for quantum lattice model solvers. It reads a simple, human-readable input file (stan.in format) and generates the detailed configuration files required by target solvers:

• HPhi: Exact diagonalization solver

• mVMC: Many-variable Variational Monte Carlo solver

• UHF: Unrestricted Hartree-Fock solver

• H-wave: H-wave quantum lattice solver

The “dry run” naming convention (e.g., hphi_dry.out) indicates that StdFace generates input files without executing the solver itself.

Source reference: README.md, src/StdFace_main.c:2-33

Design Philosophy

StdFace follows a single-source, multi-target design:

1. Unified Input Format: Users specify lattice geometry and model parameters in a simple keyword = value format.

2. Build-Time Mode Selection: The target solver is determined at compile time via preprocessor defines (_HPhi, _mVMC, _UHF, _HWAVE). This produces four separate binaries from the same source code.

3. Lattice Abstraction: Lattice-specific logic is encapsulated in dedicated constructor functions (e.g., StdFace_Chain, StdFace_Honeycomb), enabling support for multiple lattice geometries.

Source reference: src/CMakeLists.txt:17-51, src/StdFace_main.c:2915-2945

Header Location Note

Important

Unlike typical C projects, StdFace does not have an include/ directory. All header files are located in src/:

• src/StdFace_ModelUtil.h - Core model utilities (37 functions)

• src/StdFace_vals.h - Parameter structure StdIntList (~125 fields)

• src/setmemory.h - Memory allocation utilities (24 functions)

• src/export_wannier90.h - Wannier90 export (HWAVE-only, 2 functions)

• src/version.h - Version information (1 function, 4 macros)

See Directory Structure for details.

Core Components

Entry Point

The CLI entry point is main() in src/dry.c, which:

1. Parses command-line arguments

2. Handles -v for version display

3. Dispatches to StdFace_main(fname) for processing

Source reference: src/dry.c:34-47

Main Processing

StdFace_main() in src/StdFace_main.c performs:

1. Initialization: Allocates and resets StdIntList structure

2. Input Parsing: Reads keyword = value pairs from input file

3. Lattice Construction: Calls appropriate lattice function based on input

4. Output Generation: Writes solver-specific configuration files

Source reference: src/StdFace_main.c:2454-3066

Supported Lattices

StdFace supports these lattice types (each has a dedicated constructor function):

Dimension	Lattice	Function
1D	Chain	StdFace_Chain
1D	Ladder	StdFace_Ladder
2D	Square/Tetragonal	StdFace_Tetragonal
2D	Triangular	StdFace_Triangular
2D	Honeycomb	StdFace_Honeycomb
2D	Kagome	StdFace_Kagome
3D	Orthorhombic	StdFace_Orthorhombic
3D	Face-Centered Ortho.	StdFace_FCOrtho
3D	Pyrochlore	StdFace_Pyrochlore
N/A	Wannier90 import	StdFace_Wannier90

Source reference: src/StdFace_main.c:23-33, src/StdFace_ModelUtil.h

Build-Time Mode Selection

The same source code produces different binaries depending on CMake options:

CMake Option	Define	Binary	Library
-DHPHI=ON	_HPhi	hphi_dry.out	libStdFace_hphi.a
-DMVMC=ON	_mVMC	mvmc_dry.out	libStdFace_mvmc.a
-DUHF=ON	_UHF	uhf_dry.out	libStdFace_uhf.a
-DHWAVE=ON``| ``_HWAVE		hwave_dry.out	libStdFace_hwave.a

All options default to OFF. One or more may be enabled simultaneously.

Source reference: CMakeLists.txt:4-14, src/CMakeLists.txt:17-51

Thread and MPI Safety

Unspecified in the current code. The codebase does not appear to use explicit threading or MPI constructs in the src/ files examined.