GPU Accelerated INtensities MPI (GAIN-MPI): A new method of computing Einstein-A coefficients

Calculating dipole transition intensities or the related Einstein A coefficients can dominate the computer usage for large line lists of transitions such as those being computed to model radiative transport through hot atmospheres. An algorithm for the efficient computation of line strengths is presented based on the use of the half-linestrength. This is implemented on GPUs, are shown to give up to a thousandfold speed-up compared to calculations on conventional computers. This algorithm is implemented in the program GAIN which was developed as part of the TROVE nuclear motion program, but can be adapted for use by other similar programs in a straightforward fashion.

在用于模拟热大气辐射传输的大型跃迁线列表计算任务中，偶极跃迁强度或相关爱因斯坦A系数的计算往往占据绝大多数计算开销。本文提出了一种基于半线强（half-linestrength）的谱线强度高效计算算法。该算法已在图形处理器（GPU）上实现，实测表明其相较于传统计算机上的同类计算可实现最高达千倍的加速效果。该算法已集成至GAIN程序中——GAIN是作为TROVE核运动程序的组成部分开发而来，亦可通过简便方式适配至其他同类程序中使用。