as part of the deal but said he "can't comment" on the figure which was a "private business".
Basque-born Rahm said the money he was being offered by LIV was "great" but maintained that he does "not play golf for the money".
He continued: "I play golf for the love of the game and for the love of golf. I'm an ambitious person but I'm not a greedy one.
"But as a husband, as a father and as a family man I have a duty to them to give them the most amount of opportunities and the most amount of resources possible.
"Obviously, [money] is a factor and it's an important one in this decision. The love of the game and wanting to grow it in a global market. Being part of the team. Being a captain. Hopefully being a leader to team-mates. It makes me want to work harder than I have done now to actually prove myself.
"Hopefully some time in the future some kids in Spain will want to be part of this team that I am going to build. Hopefully it's something that I am related to for a very long time. Hopefully until the day I die. And I can make it something very special."
He joins several other major winners at LIV, including Brooks Koepka, who won this year's US PGA Championship, 2022 Open champion Cam Smith and six-time major winner Phil Mickelson.
In June 2023 the PGA and DP World Tours announced they had a 'framework agreement' to merge with the Saudi Arabian Public Investment Fund (PIF), which has pledged $2bn (£1.6bn) of support to LIV.
That agreement has a deadline of 31 December 2023 to be ratified, although the American government is examining the PGA Tour's plans to take massive investment from Saudi Arabia.
Implications of Rahm's switch to LIV
Rahm's decision is likely to have huge repercussions for the ongoing negotiations over the future of men's professional golf.
The Spaniard said in 2022 that LIV's three-day events, with shotgun starts and no cut, was "not appealing" and he was chasing a golfing legacy over money.
His victories in this year's Masters and the 2021 US Open guarantee him exemptions to play in all four majors for several years, but this decision puts his Ryder Cup future in jeopardy.
Rahm won three points as Europe regained the trophy with a 16½-11½ victory over the United States in Rome in September, but current DP World Tour rules would stop him from playing in the next event in 2025 and adding to his three appearances in the biennial competition.
This month he pulled out of Tiger Woods and Rory McIlroy's new TGL venture, saying it would "require a level of commitment I can't offer".
Rahm had been one of the first to commit Woods and McIlroy's high-tech indoor simulator league, which has been postponed until 2025 after its facility in Florida sustained damage.
Rahm said his decision "wasn't anything personal" against the players on the PGA Tour and "hopes the best for the future" of the sport in a "moving and changing environment" which will eventually allow him to play across both formats.
"I found a great platform on the PGA Tour and I am forever grateful for the platform they have given me," he added.
"If I'm lucky and things go well in the future, I still want to be part of that platform.
"LIV Golf gives me the freedom to play golf when it doesn't conflict with the PGA Tour or DP World Tour and I certainly want to be part of that in the future."
What has Rahm previously said about LIV?
There have been rumours about the two-time major champion joining Greg Norman's LIV set-up over the past 18 months.
According to reports, Rahm, who has $51m (£41m) in PGA Tour career earnings, has previously turned down up to $400m (£320m) to join the circuit.
He said in 2022: "Money is great, but when [my wife] Kelley and I started talking about it, we're like, will our lifestyle change if I got $400m? No, it will not change one bit.
"I could retire right now with what I've made and live a very happy life and not play golf again. So I've never really played the game of golf for monetary reasons. I play for the love of the game, and I want to play against the best in the world.
"I've always been interested in history and legacy, and right now the PGA Tour has that."
However, Rahm was one of the more outspoken players after the shock announcement of the 'framework agreement', saying at the time that a lot of PGA Tour players "feel betrayal from management".
He was also critical of LIV's European players not being allowed to compete at the Ryder Cup this year.
Under current rules, European players must be members of the DP World Tour to be eligible to play.
That rendered record points scorer Sergio Garcia, Lee Westwood and Ian Poulter ineligible after they resigned from the European tour in May in the wake of being fined and banned for their involvement with LIV.
Europe also switched captain midway through the two-year cycle after Henrik Stenson opted to join LIV, with Luke Donald taking over.
American Brooks Koepka, who won his fifth major at the 2023 US PGA Championship, was the only LIV player competing in Rome.
"It's sad politics have got in the way of such a beautiful event," said Rahm earlier this year.
"It's the best Europeans against the best Americans, period, And whatever is going on, who is playing LIV and who is not playing LIV to me shouldn't matter."