See http://premium.wpmudev.org/forums/topic/i-want-to-have-a-grid-display-for-the-blog-on-my-website?replies=39#post-781296 for details

loop.php

<?php

$ads = array(
	1 => '<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
		<ins class="adsbygoogle"
		style="display:inline-block;width:300px;height:250px"
		data-ad-client="ca-pub-5228026630530124"
		data-ad-slot="2078322417"></ins>
		<script>(adsbygoogle = window.adsbygoogle || []).push({});</script>',
	4 => '<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
		<ins class="adsbygoogle"
		style="display:inline-block;width:300px;height:250px"
		data-ad-client="ca-pub-5228026630530124"
		data-ad-slot="2078322417"></ins>
		<script>(adsbygoogle = window.adsbygoogle || []).push({});</script>',
);

?>

<?php if ( ! have_posts() ) : ?>

	<div id="post-0" class="post not-found post-listing">
		<h2 class="post-title"><?php _e( 'Not Found', 'tie' ); ?></h2>
		<div class="entry">
			<p><?php _e( 'Apologies, but no results were found for the requested archive. Perhaps searching will help find a related post.', 'tie' ); ?></p>
			<?php get_search_form(); ?>
		</div>
	</div>

<?php else : ?>

	<div class="post-listing">
		<?php $i = 0; ?>
		<?php $ad_locations = array( 1, 4 ); ?>
		<?php while ( have_posts() ) : the_post(); ?>
			<?php $i++; ?>
			<?php foreach ( $ads as $ad_position => $ad_code ) : ?>
				<?php if ( $i == $ad_position ) : ?>
					<article <?php tie_post_class('item-list'); ?>>
						<?php echo $ad_code; ?>
					</article>
				<?php endif; ?>
			<?php endforeach; ?>
			<?php if( tie_get_option( 'blog_display' ) != 'full_thumb' ): ?>
				<article <?php tie_post_class('item-list'); ?>>
					<h2 class="post-box-title"><a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'tie' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><?php the_title(); ?></a></h2>
					<?php get_template_part( 'includes/archives-meta' ); ?>					

					<?php if( tie_get_option( 'blog_display' ) == 'content' ): ?>
						<div class="entry">
							<?php the_content( __( 'Read More &raquo;', 'tie' ) ); ?>
						</div>
					<?php else: ?>
						<?php if ( function_exists("has_post_thumbnail") && has_post_thumbnail() ) : ?>			
							<div class="post-thumbnail">
								<a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'tie' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark">
									<?php the_post_thumbnail('thumbnail');  ?>
									<span class="overlay-icon"></span>
								</a>
							</div><!-- post-thumbnail /-->
						<?php endif; ?>
						<div class="entry">
							<p>
								<?php tie_excerpt() ?>
								<a class="more-link" href="<?php the_permalink() ?>"><?php _e( 'Read More &raquo;', 'tie' ) ?></a>
							</p>
						</div>
					<?php endif; ?>

					<?php if ( tie_get_option( 'archives_socail' ) ) : ?>
						<?php get_template_part( 'includes/post-share' ); ?>
					<?php endif; ?>

					<div class="clear"></div>
				</article><!-- .item-list -->
			<?php else: ?>
				<article <?php tie_post_class('item-list'); ?>>
					<?php if ( function_exists("has_post_thumbnail") && has_post_thumbnail() ) : ?>
						<div class="post-thumbnail single-post-thumb archive-wide-thumb">
							<a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'tie' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><?php tie_thumb( 'slider' ); ?><span class="overlay-icon"></span></a>
						</div>
						<div class="clear"></div>
					<?php endif; ?>
					<h2 class="post-box-title"><a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'tie' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><?php the_title(); ?></a></h2>
					<?php get_template_part( 'includes/archives-meta' ); ?>
					<div class="entry">
						<p>
							<?php tie_excerpt() ?>
							<a class="more-link" href="<?php the_permalink() ?>"><?php _e( 'Read More &raquo;', 'tie' ) ?></a>
						</p>
					</div>
					<?php if ( tie_get_option( 'archives_socail' ) ) : ?>
						<?php get_template_part( 'includes/post-share' ); ?>
					<?php endif; ?>
					<div class="clear"></div>
				</article><!-- .item-list -->
			<?php endif; ?>

		<?php endwhile;?>
	</div>
<?php endif; ?>