No credit shall be determined under this subpart with respect to any property used by an organization (other than a cooperative described in section
521) which is exempt from the tax imposed by this chapter unless such property is used predominantly in an unrelated trade or business the income of which is subject to tax under section
511. If the property is debt-financed property (as defined in section
514
(b)), the amount taken into account for purposes of determining the amount of the credit under this subpart with respect to such property shall be that percentage of the amount (which but for this paragraph would be so taken into account) which is the same percentage as is used under section
514
(a), for the year the property is placed in service, in computing the amount of gross income to be taken into account during such taxable year with respect to such property. If any qualified rehabilitated building is used by the tax-exempt organization pursuant to a lease, this paragraph shall not apply for purposes of determining the amount of the rehabilitation credit.