Three former top government officials, after calling in April for the United States to renounce first use of atomic weapons in a war, widened their proposal yesterday and called for "no hasty second use" either.

The idea, laid out in a speech here by Robert S. McNamara, who was secretary of defense in the Kennedy and Johnson administrations, is that there must be "no spasm-like nuclear response" to any country's first use of a nuclear weapon "until it has been determined beyond any possible doubt" that the explosion was "intentional and purposeful."

McNamara claimed that the United States has neglected the improvements necessary to insure communications between the leaders of atomic superpowers in such a crisis and the provisions to protect the authorities who could, in effect, call off a nuclear war.

The Reagan administration, however, has requested some $18 billion for improvements to these so-called command and control matters over the next several years, continuing a trend set in motion during the Carter administration.

McNamara, McGeorge Bundy, who was White House national security adviser during the Kennedy and Johnson years, and Gerard Smith, chief delegate to the U.S.-Soviet strategic arms limitation talks under President Nixon, were honored here yesterday as recipients of the $50,000 Albert Einstein International Peace Prize.

The three former officials published the first-use article along with George F. Kennan, a former ambassador to the Soviet Union, in last April's edition of the quarterly journal Foreign Affairs. Because Kennan won the peace prize last year he did not share in this year's award.

In the article, which itself became the subject of considerable discussion and controversy here and abroad, the authors argued that renunciation of the first use of atomic weapons would reduce both the fear and the likelihood of nuclear war, and would provide the basis for strengthening conventional forces and political unity within the Atlantic alliance which could counter the Soviet threat.

American policy for three decades has been based on the idea that the first-use threat keeps the numerically superior Soviet-led Warsaw pact forces at bay.

In presenting the award, Norman Cousins, the former editor of the Saturday Review and chairman of the peace-prize selection board, said reporters asked why the prestigious award was going to former officials who were once thought to be "hawks," meaning hardliners on defense and Soviet matters.

Cousins said that the spirit behind these awards was to recognize contributions to public understanding of crucial issues; that the country and its people are short of confidence and ideas these days, and that making people think about such life-and-death matters was of overriding importance.

Bundy claimed that the authors are more convinced than ever that their call for a study renouncing first use is necessary and has support, although there has been no official government support here or much in western Europe. McNamara said studies are under way, including some multinational studies by private institutions and universities here and abroad.

At the $200-a-plate luncheon, attended by about 225 persons including many top-level figures from former administrations, President Reagan was much criticized for suggesting this week that citizens who favor a nuclear freeze or are members of peace movements are being manipulated by outsiders.

Cousins said "the idea of Americans being manipulated by a foreign power is an undeserved compliment to that power and a slur on the American people."