Function wrap_to_first_bz

cpp_core/src/symmetry.cpp:62–64

Wrap k to [-0.5, 0.5)

// Wrap k to [-0.5, 0.5)
double wrap_to_first_bz(double x) {
    return x - std::floor(x + 0.5);
}

// Generate all 3x3 integer matrices with entries in {-1,0,1} and |det|=1.
// Returns column-major Mat3i (exactly 386 candidates).