Hi,

There is two many2one fields with comodel as account.account inside the res.partner. The field names as of odoo12 is property_account_receivable_id and property_account_payable_id.

property_account_payable_id = fields.Many2one('account.account', company_dependent=True,
    string="Account Payable", oldname="property_account_payable",
    domain="[('internal_type', '=', 'payable'), ('deprecated', '=', False)]",
    help="This account will be used instead of the default one as the payable account for the current partner",
    required=True)
property_account_receivable_id = fields.Many2one('account.account', company_dependent=True,
    string="Account Receivable", oldname="property_account_receivable",
    domain="[('internal_type', '=', 'receivable'), ('deprecated', '=', False)]",
    help="This account will be used instead of the default one as the receivable account for the current partner",
    required=True)

Thanks