Enhanced plane wave expansion analysis for the band structure of bulk modes in two-dimensional high-contrast solid–solid phononic crystals

•High contrast solid–solid phononic crystals were modeled using the plane wave expansion method that utilized the Inverse rule for obtaining the Fourier coefficients of the elastic tensor.•Utilizing the Inverse rule vs. the conventional Laurent's rule approach allows for the use of considerably less reciprocal lattice vectors (in this case <20%) to attain full convergence.•Computational times have been demonstrated to decrease by more than 6000 times using the Inverse rule approach vs. the conventional Laurent's rule approach.