The Rev. Sun Myung Moon sent a message from his jail cell to a Unification Church-sponsored conference of scientists and scholars from 46 countries here yesterday, offering his prayers for "solutions to global concerns."

The Korean evangelist is serving an 18-month sentence at the federal penitentiary in Danbury, Conn., for failing to report $162,000 in income on his federal tax returns in 1973 through 1975.

Organizers said the 13th International Conference on the Unity of the Sciences, a three-day event which began yesterday at the J. W. Marriott in Washington, was designed to help "solve the crisis of fragmentation of the sciences in the face of pressing global problems."

The Rev. Moon's wife, Hak Ja, delivered his message, telling the group of about 250 that in 1971 her husband "was called by God to come to America from South Korea and lead a movement to revive the fervor of Christianity and the founding spirit of the nation."

The all-expenses-paid gatherings of scholars from a variety of academic disciplines continue to be controversial within the scholarly community, where they generally lack any academic credibility.

"Most of us come here because we are interested in the substance of the meeting," said Karl Pribram, president of Professors World Peace Academy of the United States. "What we're here for is to try to exchange information. We're not here in order to fulfill Rev. Moon's hopes. They are two separate things."

In a brochure describing the conference, organizers said "participation in any of its programs implies neither acceptance, nor endorsement, of the tenets and activities of the Unification Church."

Its mission was defined as creating "local, regional, national and international networks of scholars and scientists who share a positive value bias and a commitment to invest their time and talents to work toward the development of human knowledge for the resolution of world problems and the development of the new world culture."