A fast and simple program for solving local Schrodinger equations in two and three dimensions

We describe a simple and rapidly converging code for solving local Schrodinger equations in two and three dimensions. Our method utilizes a fourth-order factorization of the imaginary time evolution operator which improves the convergence rate by one to two orders of magnitude compared with a second-order Trotter factorization. We present the theory behind the method and strategies for assessing convergence and accuracy. Our code requires one user defined function which specifies the local external potential. We describe the definition of this function as well as input and output functionalities.