A major downtown Washington museum to commemorate the 6 million Jews and 5 million other civilians murdered by the Nazis during World War II has been proposed by the 34-member Commission on the Holocaust, created by President Carter last November.

The proposed muesum and a Holocaust educational foundation, privately estimated to cost at least $40 million to $50 million, would be connected with the Smithsonian Institution, if the president and Congress follow the recommendations of the commission.

Funds needed for the museum's construction would come from contributions, with the federal government providing $1 million in seed money, land for the museum in Washington and an unspecified amount of matching grants, according to the 50-page report to be officially presented to the president today in a 2 p.m. ceremony at the White House. Contributions would fund the museum's operating costs, under the report's recommendations.

While the museum would focus on the victims of the Holocaust, "it would not be a museum of horrors, of the macabre. . .with skeletons," Holocaust staff assistant Marian Craig said yesterday. Although photographs of concentration camps and their victims would be displayed, as they are in a similar museum in Israel, Craig said the displays would be tasteful.

Elie Wiesel, commission chairman, novelist and survivor of Auschwitz and Buchenwald concentration camps, says in a letter to the president accompanying the report: "We wish . . . [through the museum and education efforts] to reach and transform as many human beings as possible. We hope to share our conviction that when war and genocide unlease hatred against any one people or peoples, all are ultimately engulfed in the fire."

Although Carter established the commission after last summer's premiere of the television movie "Holocaust" -- shown again this month -- Holocaust Commission spokeswoman Craig said "the commission is not a spin-off of the movie, but we have profited from it. People are much more aware."

"Why it has taken so long . . . 35 years since the end of World War II . . . for some kind of memorial to the victims of the Holocaust, I don't know," Craig said. "Perhaps it's difficult for Americans to feel moral responsibility for it. But President Carter is a human rights president and a moralist and only now is the issue being brought out."

The commission, which includes 10 members of Congress and a 27 member advisory board comprising experts and many survivors of Nazi death camps, visited Poland, the Soviet Union, Denmark and Israel earlier this year to see existing memorials to Holocaust victims.

They visited Treblinka, where 800,000 Jews were killed, which is commemorated by a stone monument; the still-standing Auschwitz, and Babi Yar in Kiev, where 80,000 Jews were shot and thrown in a ravine. A Russian memorial marks the site but makes no reference to the fact that most of the victims were Jews.

The proposed Washington memorial museum is modeled somewhat on the Yad vashem museum and study center in Jerusalem, Craig said. It has archives, research and educational facilities, all items the proposed Washington museum and educational foundation will have.

The Washington foundation would "research and explore issues raised by the Holocaust for all areas of human knowledge and public policy," the report says.

A "Committee on Conscience" also is proposed by the commission, which would be composed of "distinguished moral leaders in America" who would study reports of genocide anywhere in the world.

The Vietnamese "boat people" are cited as an example of threatened people and earlier this year commission chairman Wiesel appealed directly to President Carter to intervene on their behalf. The commission report says the Committee on Conscience could help alert the world to atrocites and possibly help avoid another "Evian." Evian was the site of the 32- nation conference in France in 1938 "that failed to rescue the Jews when Hitler flung that challenge in the world's face," the report says.

The commission report does not detail what the proposed Holocaust museum would contain or where it might be located. President Carter, when he established the commission, asked only that it report about "an appropriate memorial."

a spokesman for the Smithsonian, Lawrence Taylor, said the "Smithsonian's role has not been determined." Smithsonian Secretary S. Dillon Ripley met briefly with commission staff in May, but Taylor said the museum idea is something the Smithsonian staff, Congress and Holocaust Commission members would have to study further.

The commission, after a seven-month life span, goes out of existence on Friday, but commission staffer Craig said, "We hope the president will appoint a successor body to help draft legislation" and pursue the Holocaust Commission's goals. Craig said all 10 congressional members of the commission support the museum idea and are planning to write a letter supporting it.