280-20-20 R.I. Code R. § 12.5
The research and development deduction shall be allowed only on condition that entire net income for the taxable year and all succeeding taxable years be computed without the deduction of any such expenditures allowed for federal purposes and without any deduction for depreciation of the same property except to the extent that its basis may be attributable to factors other than such expenditures. In case only a part of the deduction for research and development facilities is allowable pursuant to this section and a deduction is fully allowable for federal income tax purposes, then such expenditures and depreciation as allowed for federal purposes shall be proportionately reduced for the taxable year and all succeeding taxable years.
280 R.I. Code R. § 280-RICR-20-20-12.5