Rock for the betterment of the world at Planet Gemini.

When reggae-rock-hip-hop outfit Atomixx formed earlier this year, their vision of the future wasn’t soaked in all-night parties and scantlily clad groupies. Their motivation is pure-hearted:

“We’re not doing this for financial gain,” says bassist and founder Mike Royster. “We just try to make people happy.”

Royster, a special needs teacher at Monterey High, says Atomixx began very casually as a few friends playing reggae-rock. There wasn’t any intention of even playing in public, but the outfit struck a deal with Planet Gemini that changed that: Now the band performs regularly there in exchange for rehearsal space.

Last June, Royster saw Atomixx’s true calling with a Surfrider Benefit, the first of what he’s dubbed the “Benefit Series.”

“We’re gonna rock out anyway, so we might as well rock out for a good cause,” he says.

Tonight, good will at Planet Gemini continues with Rock for Autism, which will donate all proceeds to nonprofit Monterey Peninsula Autism Assistance.

Atomixx headlines with a mix of eclectic covers, including Supersuckers’ “Born With a Tail” and Social Distortion’s “Prison Bound,” and unexpected mashups, like LL Cool J rhymes over Hendrix riffs, courtesy of the band’s featured rapper Sergio.

“We’re all about trying to keep everything fresh,” Royster says.

Also on the bill: The Death Cats, Metallica-meets-The Doors all the way from Arizona, and DJ BBB rounds out the roster behind the turntables.

Royster already has several future benefits in the works. On Sept. 25, there will be a fundraiser for rescue dogs. Benefits for veterans and needy children are also on the horizon. Atomixx meanwhile, has no plans to record any albums or tour. They play live and they play for a cause.

“It’s all about love, positivity and trying to help people,” Royster says.

ROCK FOR AUTISM 8pm Thursday, Aug. 28. Planet Gemini, 2110 N. Fremont Ave., Monterey. $5 donation. www.communitygivinginitiative.com