1Dept. of Physics and Astronomy, University of Georgia, Athens, GA 30602-2451; yeti@hal.physast.uga.edu
2Dept. of Physics and Astronomy, Arizona State University, Tempe, AZ 85287-1504
3Dept. of Physics and Astronomy, University of Oklahoma, 440 W. Brooks, Rm 131, Norman, OK 73019-0225; baron@phyast.nhn.ou.edu
4Dept. of Physics, Wichita State University, Wichita, KS 67260-0032; allard@eureka.physics.twsu.edu
We describe the parallel implementation of our generalized stellar atmosphere and NLTE radiative transfer computer program PHOENIX. We discuss the parallel algorithms we have developed for radiative transfer, spectral line opacity, and NLTE opacity and rate calculations. Our implementation uses a MIMD design based on a relatively small number of MPI library calls. We report the results of test calculations on a number of different parallel computers and discuss the results of scalability tests.